Officials in the Democratic Republic of Congo say two U.N. officials, one American and one Swedish, have been kidnapped along with four Congolese in Kasai Central province.

Government officials identified the U.N. officials as Michael Sharp of the United States and Zahida Katalan of Sweden. They said the kidnappers have not yet been identified.

United Nations officials in New York would not confirm the two were kidnapped but said the U.N. mission in the DRC, MONUSCO, has begun a search.

“Two members of the group of experts team are missing. MONUSCO is looking for them,” a U.N. spokesman said.

Officials in Kasai Central say they have opened an investigation into the matter.

MONUSCO’s mandate is to help Congo’s government stabilize the country, which is home to many militia and rebel groups. The mission has about 800 foreign civilian staffers in addition to 20,000 soldiers and police.