The Organization for Security and Cooperation in Europe (OSCE) has lost contact with a five-member team in east Ukraine, where four members of another OSCE mission are still being held by pro-Russian forces, the Associated Press reported.

The OSCE said in a statement online Friday, May 30, that it had lost contact with the team, made up of four international workers and one Ukrainian translator, late on Thursday. The OSCE has been without contact with another four-member team since Monday.

A pro-Russian leader confirmed Thursday that monitors from the first group were in their custody. The activists assured journalists that they would "deal with this and then release them," but did not give a specific timeframe.