Tribal fighters in the eastern Democratic Republic of Congo have released the country's human rights minister, who they took hostage last Thursday.

Congolese Human Rights Minister Ntumba Luaba-Lumu returned unharmed to the capital, Kinshasa, late Sunday. Government officials say that the minister was kept under armed guard, but was treated well during the four days he was held captive.

Militiamen of the Hema ethnic group captured Mr. Ntumba while he was mediating peace talks Thursday in the eastern Ituri region, which was the scene of clashes between ethnic Hemas and Lendus last month.

The fighting left more than 100 people dead in the town of Bunia.

The government in Kinshasa says it freed 10 Hema militiamen in exchange for Mr. Ntumba's release.

Ethnic fighting in the Democratic Republic of Congo has hampered efforts to end a four-year civil war, which began when Uganda and Rwanda stepped in to help rebels overthrow the Kinshasa government which was supported by Zimbabwe, Angola, and Namibia.

Mr. Ntumba's release followed a Congolese government request for Uganda to intervene with the militiamen. Analysts see Uganda's help as a sign of improving relations. The two countries signed a peace accord on August 15.

Uganda, which has controlled Ituri and much of northeastern Congo, on Saturday announced it had completed the withdrawal of its troops from Congo. But several hundred remained at the request of the United Nations to assist in peacekeeping efforts.