Two missile strikes hit targets on Saturday evening in Lviv, a western Ukrainian city about 50 miles from the Polish border. Smoke was seen rising in the eastern part of the city, above what is believed to be an oil storage facility.

“There were two rocket strikes within Lviv,” Maksym Kozytsky, chairman of the Lviv regional administration, said.

“Information that hitting a residential building or other infrastructure facilities was not confirmed. According to preliminary data, five people were injured.”

The attack came as President Biden was in Warsaw wrapping up a visit to Europe intended to bolster unity over Russia’s invasion of Ukraine. Biden said the US treated its duty to defend Nato allies as “a sacred obligation”.