A "couple dozen" cruise missiles were launched from bombers flying over Russia to the Yavoriv overnight Saturday, killing 35 people and wounding 134.

The base was located west of Lviv and just 20 kilometers (12 miles) from Ukraine's border with EU and NATO member Poland.

The strike made clear that western Ukraine, largely spared so far since Russian forces invaded on February 24, was vulnerable especially from long-range missiles.

The official, speaking on condition of anonymity, said the strike was an example of how a no-fly zone over Ukraine "would have had no effect."

Kyiv and some people in countries support

ing Ukraine have called for the institution of a no-fly zone over the country to prevent attacks from the air.

But the United States and NATO allies say creating a no-fly zone would require the US or NATO to shoot down any Russian aircraft violating the zone, potentially expanding the war to most of Europe and the United States.

The Pentagon says there were no Americans at the Yavoriv base, which is used for training.

The strike did not hinder the shipment of Western weaponry and munitions to Ukraine forces, the official said, adding that deliveries took place during the past weekend.

The official stressed that the Yavoriv base was not involved in the weapons shipments.

"The strikes on Yavoriv will not affect that," the official said, referring to arms deliveries.