U.S. staff at the Organization for Security and Cooperation in Europe (OSCE) started to withdraw in cars from Donetsk in eastern Ukraine on earlier Sunday, Reuters reported, citing a witness.

Exclusive Reuters video showed staff members loading official vehicles with luggage and driving away. The OSCE did not respond to a request for comment.

The OSCE's Special Monitoring Mission to Ukraine has been deployed in the east of the country since 2014.