Rescuers were seeking to evacuate more civilians from tunnels beneath a sprawling steel mill in Mariupol as Ukrainian fighters make their last stand to prevent Moscow’s complete takeover of the strategically important port city.

Dozens of people were evacuated Friday from the Azovstal plant and handed over to representatives of the United Nations and the International Committee of the Red Cross, Russian and Ukrainian officials said. The Russian military said the group of 50 included 11 children.

Russian officials and Ukrainian Deputy Prime Minister Iryna Vereshchuk said the evacuation efforts would continue into the weekend. The latest evacuees followed roughly 500 other civilians who got out of the plant and city in recent days.

The fight for the last Ukrainian stronghold in a city reduced to ruins by the Russian onslaught appeared increasingly desperate. And there was growing speculation that President Vladimir Putin wants to finish the battle for Mariupol so he can present a triumph to the Russian people in time for Monday’s Victory Day, the biggest patriotic holiday on the Russian calendar.

As the holiday commemorating the Soviet Union’s World War II victory over Nazi Germany approached, cities across Ukraine prepared for an expected increase in Russian attacks, and officials urged residents to heed air raid warnings.

“These symbolic dates are to the Russian aggressor like red to a bull,” said Ukraine’s first deputy interior minister, Yevhen Yenin. “While the entire civilized world remembers the victims of terrible wars on these days, the Russian Federation wants parades and is preparing to dance over bones in Mariupol.”

Ukrainian President Volodymyr Zelenskyy also reminded people not to go into forests that were recently under Russian occupation because of the many land mines and trip wires that remain.