Russian President Vladimir Putin promised on Thursday to grant the civilians in Mariupol safe passage. They have been holed up in a steel plant for weeks, taking refuge alongside Ukrainian fighters.

Russian commanders have been shelling the site. They promised to stop firing during the daytime for three days. They said they would allow civilians to escape.

The Ukrainians said the Russians did not honor their promises. The deputy commander of the Azov Battalion, Sviatoslav Palamar, said "heavy, bloody fighting continues."

UN Secretary-General Antonio Guterres said aid workers have helped nearly 500 civilians to flee over the past week. He said they have mounted another operation to ferry people to safety.

On Monday, Russians will mark the World War Two triumph over Germany on what they call "Victory Day." Their leaders are using the occasion to channel national pride. Some fear the troops in Mariupol will mount a final push to seize control.