Foreign military instructors worked at the Yavoriv military facility near the Polish border that was hit by a Russian air strike on Sunday, Ukrainian Defence Minister Oleksii Reznikov said, but it was not clear if any were present at the time.
A ministry representative told Reuters the ministry was still trying to establish if any of the instructors were at the centre at the time of the attack.
"Russia has attacked the International Center for Peacekeeping & Security near Lviv. Foreign instructors work here. Information about the victims is being clarified," Reznikov said in an online post.
(Reporting by Pavel Polityuk; Writing by Alessandra Prentice; Editing by Frances Kerry)