(NewsNation) — As it continued its barrage of the besieged city of Mariupol, Russia demanded Monday that Ukrainians put down their arms and raise white flags in exchange for safe passage out of town.

Ukrainians angrily rejected the offer, which came hours after officials said Russian forces had bombed an art school that was sheltering some 400 people.

While the fight for control of the strategically important city remained intense, Western governments and analysts see the broader conflict shifting to a war of attrition.

Russian Col. Gen. Mikhail Mizintsev said it would allow two corridors out of Mariupol, heading either east toward Russia or west to other parts of Ukraine.

Mariupol residents were given until 5 a.m. Monday to respond to the offer. Russia didn’t say what action it would take if it was rejected.

But Ukrainian Deputy Prime Minister Irina Vereshchuk responded with a firm “nyet.”

“There can be no talk of any surrender, laying down of arms. We have already informed the Russian side about this,” she told the news outlet Ukrainian Pravda. “I wrote: `Instead of wasting time on eight pages of letters, just open the corridor.’”

Mariupol Mayor Piotr Andryushchenko also rejected the offer, saying in a Facebook post he didn’t need to wait until morning to respond and cursing at the Russians, according to the news agency Interfax Ukraine.

The attack on the art school was the second time in less than a week that city officials reported a public building where residents had taken shelter coming under attack. A bomb hit a Mariupol theater with more than 1,300 believed to be inside Wednesday. There was no immediate word on casualties from the reported strike on the art school.

Mariupol, a strategic port on the Azov Sea, has been under bombardment for at least three weeks and has seen some of the worst attacks of the war in Ukraine. At least 2,300 people ther ehave died.

“It is scary, very scary — especially for children,” said Ukrainian refugee Olga Bezdetko. “They are shooting everywhere. They don’t care about children nor (the) elderly. It is difficult to return because everything has been destroyed.”

Ukrainian President Volodymyr Zelenskyy early Sunday accused Russia of war crimes over its siege, describing the attack on Mariupol as “a terror that will be remembered for centuries to come.”

Zelenskyy also called on Israel to take a stronger stand against Russia, delivering an emotional appeal to the country’s leaders that compared Russia’s invasion of his country to the actions of Nazi Germany.

“When the Nazis invaded Europe and wanted to destroy everything and everyone, conquer nations and leave nothing of us and you, no name and any traces, they called it the ‘final solution of Jewish question,'” Zelenskyy said, “You remember it and will never forget it for sure. But you should hear what is coming from Moscow now, they are saying the same words now. ‘Final solution,’ but this time it’s about us, about the Ukrainian question.”

In a speech to Israeli lawmakers over Zoom, Zelenskyy said it was time for Israel, which has emerged as a key mediator between Ukraine and Russia, to finally take sides. He said Israel should follow its Western allies by imposing sanctions and providing arms to Ukraine.

“One can ask for a long time why we can’t accept weapons from you or why Israel didn’t impose sanctions against Russia, why you are not putting pressure on Russian business,” he said. “It is your choice, dear brothers and sisters.”

A total of 7,295 people were evacuated from Ukrainian cities through humanitarian corridors Sunday, Ukraine’s Deputy Prime Minister Iryna Vereshchuk said, with four out of seven planned routes working.

Of the total, 3,985 people were evacuated from the besieged city of Mariupol to Zaporizhzhia city. The Ukrainian government planned to send nearly 50 buses to Mariupol on Monday for further evacuations, Vereshchuk said.

In major cities across Ukraine, hundreds of men, women and children have been killed in Russian bombardments, while more than 3.4 million civilians have fled the country.

In the capital, Kyiv, at least 20 babies carried by Ukrainian surrogate mothers are stuck in a makeshift bomb shelter, waiting for parents to travel into the war zone to pick them up. The infants, some just days old, are being cared for by nurses who cannot leave the shelter because of constant shelling by Russian troops who are trying to encircle the city.

Several explosions were heard in Kyiv late Sunday, according to CNN’s team on the ground.

In the hard-hit city of Sumy, authorities evacuated 71 orphaned babies through a humanitarian corridor, regional governor Dmytro Zhyvytskyy said Sunday. He said the orphans, most of whom need constant medical attention, would be taken to an unspecified foreign country.

Russian shelling also killed at least five civilians, including a 9-year-old boy, in Kharkiv.

“I’d like to believe my house is still intact,” said Angelica Gretsai, a Ukrainian refugee, “my relatives and friends still alive because at this moment we don’t know what’s going to happen to Kharkiv. They bomb there constantly.”

The British Defense Ministry said Russia’s failure to gain control of the skies over Ukraine “has significantly blunted their operational progress,” forcing them to rely on weapons launched from the relative safety of Russian airspace.

A rocket attack on the Black Sea port city of Mykolaiv early Friday killed as many as 40 marines, a Ukrainian military official told The New York Times, making it one of the deadliest single attacks on Ukrainian forces.

In a separate strike, the Russian Defense Ministry said a Kinzhal hypersonic missile hit a Ukrainian fuel depot in Kostiantynivka, a city near Mykolaiv. The Russian military said Saturday that it used a Kinzhal for the first time in combat to destroy an ammunition depot in the Carpathian Mountains in western Ukraine.

Russia has said the Kinzhal, carried by MiG-31 fighter jets, has a range of about 1,250 miles and flies at 10 times the speed of sound. Pentagon press secretary John Kirby said Saturday that the U.S. couldn’t confirm the use of a hypersonic missile in Ukraine.

Still, strong Ukrainian resistance has persisted since the start of the invasion Feb. 24. At least 902 civilians have been killed and 1,459 injured in Ukraine as of midnight local time on March 19, the U.N. human rights office (OHCHR) said on Sunday, though they concede the actual toll is likely much higher.

Estimates of Russian deaths vary widely, but even conservative figures are in the low thousands. The reported battlefield deaths of four Russian generals, out of an estimated 20 deployed in Ukraine, suggest an impaired command of the fighting, said Dmitry Gorenburg, a researcher on Russia’s security at the Virginia-based CNA think tank. Gorenburg said.

Ukraine and Russia have held several rounds of negotiations aimed at ending the conflict, but the neighboring countries remain divided over several issues. Zelenskyy has said he is willing to drop Ukraine’s bid to join NATO but wants certain security guarantees from Russia. Moscow is pressing for Ukraine’s complete demilitarization.

Also Sunday, Zelenskyy ordered the activities of 11 political parties with links to Russia to be suspended during the period of martial law. The largest of those parties has 44 out of 450 seats in the country’s parliament.

“Activities by politicians aimed at discord and collaboration will not succeed,” he said in the address.

The Associated Press and Reuters contributed to this report.