Updated

The United Nations mission in Congo says the bodies of American and Swedish experts have been repatriated to their countries of origin.

The U.N.'s deputy special representative for Congo, David Gressly, said Wednesday that investigations have opened into the deaths.

American Michael Sharp, Swedish national Zaida Catalan and local interpreter Betu Tshintela went missing March 12 in Central Kasai province while looking into recent large-scale violence by the army and militia groups.

Their bodies were found last week.

President Joseph Kabila on Wednesday promised punishment for those responsible.