Ukraine has rejected an ultimatum to surrender the besieged city of Mariupol after a deadline set at 5 a.m. Moscow time (10 a.m. ET) passed. Meanwhile, shelling has continued in Kyiv this morning and at least eight people were reported killed in an attack on a shopping center in the capital.

Ultimatum rejected: The Ukrainian government and Mariupol city authorities rejected terms set out by Russia demanding the surrender of the besieged southern city to Russian forces. A deadline, set at 5 a.m. in Moscow (10 p.m. ET), came and went. “There can be no discussion of any surrender or of laying down arms,” Ukraine’s Deputy Prime Minister Irina Vereshchuk said.  

Mariupol art school bombing: Also in Mariupol, an adviser to the city’s mayor said officials are struggling to find out how many people survived after an art school being used as a shelter was bombed by Russian forces on Sunday morning. An earlier estimate from the city council put the number sheltering in the school at 400. Vereshchuk said 7,295 people fled from the city through evacuation corridors on Sunday.

Eight killed following explosions in Kyiv: At least eight people were killed in a Russian attack on a shopping center in Kyiv’s Podilskyi district, according to information from the Ukrainian Prosecutor General. That number was based on what the Prosecutor General called preliminary information, suggesting the number could rise. CNN’s team on the ground heard several explosions in Kyiv on Sunday, and the city’s Mayor Vitali Klitschko said explosions in the Podil neighborhood targeted residential and business areas.

Zelensky open to talks with Putin: Ukrainian President Volodymyr Zelensky told CNN he is ready to negotiate with Russian President Vladimir Putin, but warned that if any negotiation attempts fail, it could mean the fight between the two countries would lead to “a third World War.” “I’m ready for negotiations with him. I was ready for the last two years. And I think that without negotiations, we cannot end this war,” said Zelensky.

Ukraine summits: US President Joe Biden and fellow world leaders will hold a set of emergency summits in Europe this week. But few observers believe anything they can agree upon will be enough to end the bloodshed in Ukraine. Biden has “no plans” to visit Ukraine, the White House says, but he will travel to Warsaw, Poland following meetings with NATO allies, G7 and European Union leaders.