KINSHASA UN peacekeepers reacted with force to quash a violent protest by supporters of Jean-Pierre Bemba, the defeated candidate in last month’s presidential election in the Democratic Republic of Congo. The UN troops fired teargas and warning shots in Kinshasa, the ruined capital, but order was restored late in the afternoon. There were no apparent casualties but part of the Supreme Court was set on fire. There has been tension since President Kabila was elected in a run-off vote.