A retaliatory attack by Hutu rebels killed at least 200 Tutsis on Saturday, including many children, Radio Burundi and the army said.

The Burundian army, meanwhile, forced 1,800 Rwandan refugees back into Rwanda and rounded up thousands more on a football field while their refugee camp was ransacked by local residents, U.N. aid officials said in Geneva.

Ethnic violence is rife in Burundi, where Hutus make up 85 percent of the population of 6 million and Tutsis make up 14 percent. More than 150,000 Burundians have been killed in fighting since 1993.

The tensions threaten to erupt into a replay of the 1994 genocide in neighboring Rwanda, which has a similar ethnic makeup. More than 500,000 people were killed there, mostly Tutsis.

After the massacres, hundreds of thousands of Rwandans, mainly Hutus, fled to neighboring countries. Burundi still has about 75,000 Rwandan refugees.

Saturday’s attack took place near Bugendana, 45 miles northeast of the capital Bujumbura, in a region where at least 200 Hutus were reported killed by the Tutsi-dominated army in June. The army called the attacks retaliatory.

“Masses of rebels attacked in what seems to be an organized attack,” army spokesman Hilira Ninewa said.

Radio Burundi said the victims were Tutsis displaced by Burundi’s ethnic violence.

In Geneva, the U.N. High Commissioner for Refugees said it had brought trucks to the Kibezi refugee camp in northern Burundi on Friday to persuade the Rwandan refugees there to go home.

They refused, but after the delegation left, soldiers forced 1,800 people onto the agency’s trucks. They made the drivers take them across the Rwandan border.