Interception units across Kyiv are working nightly as hundreds of Russian drones target the Ukrainian capital, according to volunteers who join in the defense effort.

KYIV, Ukraine (AP) — Russia unleashed a major missile and drone barrage on Kyiv early Friday, killing six people, leaving gaping holes in apartment buildings and starting fires as the sound of explosions boomed across the city and lit up the night sky.

A Russian-flagged tanker loaded with sunflower oil reported a drone attack off the Turkish coast on Tuesday, but its 13 crew members were unharmed, Turkey's maritime authority and the Tribeca shipping agency said.

The latest assault on Kyiv came as Ukrainian peace negotiators are due to meet their U.S. counterparts this weekend.