The United States believes a surface-to-air missile originating from inside Russia likely shot down the plane presumed to be carrying mercenary leader Yevgeny Prigozhin, two U.S. officials told Reuters.

The officials, who spoke on condition of anonymity given the sensitivity of the matter, stressed that the information was still preliminary and under review.

Russian air authorities have said Prigozhin, his right-hand man Dmitry Utkin and eight other people were on the private plane that crashed with no survivors north of Moscow on Wednesday.