Ukraine-Russia war latest: Russian fighter jets 'intercept US bombers'; Putin's forces launch 'double tap' attack

That's all for our live updates on the war in Ukraine for today. 

We'll be back tomorrow with all the latest. 

In the meantime, here's a reminder of today's key events: 

• Ukraine said Russia was "testing new tactics" after it launched its fifth drone attack on Kyiv in two weeks;
• Russian fighter jets stopped two US strategic bombers from violating the country's airspace, Moscow's defence ministry said;
• Volodymyr Zelenskyy reiterated calls for countries to provide Ukraine with long-range weapons after Russia's overnight drone and missile attack;
• Russian state media reported Moscow's troops had captured two settlements in Ukraine - Rozivka, in Ukraine's eastern Luhansk region, and Pishchane Nizhne in the northeastern Kharkiv region;
• Russian forces launched a "double tap" attack on first responders in Sumy, the Ukrainian state emergency service said;
• Mayor of Kyiv Vitaliy Klitschko warned the Ukrainian president faces "a very difficult" time in the coming months. 

Ukraine is developing AI systems to help fly a vast fleet of drones. 

A number of startups in the country are working to roll out AI-enabled drones across the front line in the hope of overcoming Russia's unmanned aerial vehicle power. 

Swarmer is developing software that links drones in a network, allowing decisions to be implemented instantly across the group. 

"For a swarm of 10 or 20 drones or robots, it's virtually impossible for humans to manage them," Swarmer chief executive Serhiy Kupriienko told Reuters. 

The company is one of more than 200 tech firms that have sprung up since the war started. 

Mr Kupriienko said that while human pilots struggle to run operations involving more than five drones, AI will be able to process hundreds.

The system, called Styx, directs a web of reconnaissance and strike drones, both large and small, in the air and on the
ground. 

Every drone would be able to plan its own moves and predict the behaviour of the others in the swarm, he explained. 

Swarmer's technology is still under development and has only
been trialled on the battlefield experimentally, he added. 

Two Ukrainian photojournalists have been injured after coming under Russian fire. 

Olga Kovalyova and Vladyslav Krasnoshchok had been documenting the situation in Donetsk from a trench near the front line when they came under attack. 

Ms Kovalyova, who works for the Ukrainian Association of Professional Photographers (UAPP), was evacuated and hospitalised after being hit by shrapnel, the organisation said. 

"I was saved by a bulletproof vest and a helmet. The shrapnel got to a place where there was no protection," Ms Kovalyova said, according to UAPP's statement. 

"It's a pity that it happened on the first day of the business trip."

Mr Krasnoshchok suffered a concussion but did not require hospital treatment, it added. 

Volodymyr Zelenskyy will face a "very difficult" time over the coming months, the mayor of Kyiv has warned. 

Speaking to Italian news outlet Corriere della Sera, Vitaliy Klitschko said the Ukrainian president will have to make hard decisions that could lead to "political suicide". 

He warned that Mr Zelenskyy may have to launch a referendum in Ukraine if a territorial compromise with Russia is put on the table. 

"The coming months will be very difficult for Volodymyr Zelenskyy," he said. 

"Will he have to continue the war with new deaths and destruction, or consider the possibility of a territorial compromise with Putin?" 

"Whatever move he makes, our president risks political suicide. Let's be honest, we have to win the war, but the situation is getting more and more difficult. It depends on the help that comes from the allies. It would be a nightmare if we had to fight for two more years." 

More than 270 Ukrainian Telegram channels have been hacked today, news outlets in the country have reported. 

Hackers sent a message to Ukrainians telling them to "lay down their arms", according to Suspilne. 

Messages also appeared accusing Volodymyr Zelenskyy of starting the war, it said. 

In a Facebook post, Ukraine's state security service said the cyberattack was carried out by the Russian FleepBot service. 

"On July 21, mass publication of messages of a provocative nature was recorded in a number of well-known Ukrainian Telegram channels that used the FleepBot software to post news," it wrote. 

"We would like to once again emphasize the danger of using any software of the aggressor country."

FleepBot is a Telegram tool that allows users to schedule posts to go out automatically. 

Russian forces have launched a "double tap" attack on first responders in Sumy, the Ukrainian state emergency service has said.

Emergency workers had been dealing with the aftermath of an overnight missile attack on the northeastern city when they came under fire. 

They were extinguishing one of five fires at a residential building at the time, the service said. 

No casualties have been reported. 

The "double tap" tactic, which has been used by Russia throughout the war, sees an area come under a second attack shortly after an initial strike. 

In several cases, the second attack has come while rescuers are trying to help those who have been injured. 

In March, more than 20 people were killed in the southern city of Odesa in a "double tap" attack. 

At the time, Ukrainian President Volodymyr Zelenskyy described it as a "despicable act of cowardice". 

By Lara Keay, news reporter

The establishment of the "axis powers" in the 1930s paved the way for the Second World War.

Agreements signed between Germany, Italy, and Japan in 1936 united them in their expansionist interests and hatred of Western allies.

Amid Russia's war in Ukraine, the Israel-Hamas conflict, and China's repeated threats of invading Taiwan, some security and military analysts say we are on a similar path again and that Russia, China, Iran, and North Korea are the "new axis powers".

The last time a similar term was used was in 2002 by former US President George W Bush, describing Iran, Iraq, and North Korea, as an "axis of evil" in the wake of 9/11.

Ahead of a new UK defence review, former defence secretary and NATO leader Lord Robertson described Russia, China, Iran, and North Korea as a "deadly quartet".

There have also been warnings more than one of them risks triggering a third world war within the next five years.

Here Sky News looks at the risk they pose and how it could affect life in the UK...

People living in the Russian-occupied Donetsk region have been left without water, a Ukrainian organisation has said. 

The region was illegally annexed by Russia in 2022, but is not fully controlled by Moscow. 

When Russian troops occupied the area, they attempted to build a pipeline to pump water from the River Don to the region. 

But the Ukrainian Centre of National Resistance has said the pipeline has stopped working due to a power outage. 

It claimed there had been ongoing issues with the system due to fighting in the region, but repairs have taken months and the situation has "worsened". 

"Due to the power outage in Russia, the pumping stations of the newly built canal have failed, and the water supply has stopped completely," it said. 

Russian troops have captured two settlements in Ukraine, state media has reported. 

The village of Rozivka, in Ukraine's eastern Luhansk region, and Pishchane Nizhne in the northeastern Kharkiv region have both been taken, according to the reports. 

TASS news agency said both villages were captured in one day. 

It quoted the Russian defence ministry as saying: "As a result of successful actions, units of the West group of troops liberated the settlements of Rozivka in the Luhansk People's Republic and Pishchane Nizhne in the Kharkiv region, and also occupied more advantageous lines and positions." 

Russia illegally annexed Luhansk and three other regions (Donetsk, Kherson, and Zaporizhzhia) in 2022. 

The international community still recognises the areas as part of Ukraine. 

Kharkiv has been one of Russia's targets since the early days of the war, but the region became more of a focal point in May when Moscow's forces launched a cross-border incursion. 

Ukrainian officials have previously said the incursion had been contained, with Volodymyr Zelenskyy saying the Kharkiv advance had been "halted" in an address to world leaders earlier this week. 

Yesterday, former Ukrainian legislator Iryna Farion died after being shot in the street by an unknown assailant. 

The 60-year-old initially survived the assault in the western city of Lviv on Friday, but later died in hospital. 

A manhunt has been under way for her attacker, who fled from the scene.

Ukrainian officials said the attack was being treated as an assassination.

So who was Iryna Farion? 

Ms Farion was a member of the Ukrainian parliament between 2012 and 2014.

She was best known for her campaigns to promote the use of the Ukrainian language by Ukrainian officials who spoke Russian.

While many praised her efforts as attempts to sever ties with Russia, others viewed her methods as dividing the Ukrainian people. 

Late last year, she caused uproar by saying Russian-speaking Ukrainian soldiers were not "real Ukrainians". 

She also controversially criticised Russian-speaking members of Ukraine's Azov regiment, who defended the port city of Mariupol in the first days of the full-scale invasion.

Police have been considering "personal animosity" toward the former MP due to her social and political activities as a likely motive behind the attack.