Russian forces launched a missile attack on a large Ukrainian military facility near the Polish border on Sunday, Ukrainian officials said, in what appeared to be the westernmost attack of the war.

"The occupiers launched an airstrike on the International Center for Peacekeeping and Security" in Yavoriv, the Lviv regional military administration said in a statement. "According to preliminary data, they fired eight missiles."

Reuters was unable immediately to verify the report and Russia offered no immediate comment.

Initial reports indicated...