U.N. officials say peacekeepers in the Democratic Republic of Congo have killed more than 50 militiamen in a gun battle in the troubled northeastern Ituri province.

A U.N. spokesman said Wednesday that the clash occurred Tuesday, some 30 kilometers from the town of Bunia. The spokesman said the U.N. forces responded using an attack helicopter.

The clash comes one week after nine peacekeepers from Bangladesh were killed by militiamen in the same area. Congolese security forces announced Tuesday that they arrested militia leader Floribert Ndjabu in the capital, Kinshasa and are questioning two other suspects in connection with the killings Mr. Ndjabu is the leader of the ethnic Lendu militia known as the Nationalist and Integrationist Front. It is one of several militias operating in eastern Congo.