Kyiv, Ukraine (CNN) — Ukraine says it was struck by a new barrage of deadly Russian air attacks as an Easter ceasefire ended and as the US pushes for a deal between Moscow and Kyiv to end the three-year-long conflict.

At least three people were killed and several wounded in Russian attacks in the southern Kherson region, said the head of its regional military administration, Oleksandr Prokudin.

Blasts also rocked the nearby southern port city of Mykolaiv early Monday, according to its mayor, with air alerts issued for several eastern regions.

“Explosions were heard,” Mayor Oleksandr Senkevych said on Telegram. It was not immediately clear whether there were any casualties or the extent of the damage.

Meanwhile, at least four people were wounded in the eastern Donetsk region, according to the head of its regional military administration, Vadym Filashkin.

The attacks came hours after the expiration of an Easter ceasefire called by Russian President Vladimir Putin, which both sides accused each other of violating.

The surprise truce came after the US on Thursday submitted its latest proposal in its so far fruitless efforts to broker a peace deal between Ukraine and Russia.

Part of the proposal submitted to Kyiv and its European allies at high level talks in Paris would see the Trump administration ready to recognize Russian control of Crimea, which Moscow annexed in 2014, an official familiar with the framework told CNN.

Crimea in southern Ukraine has been under Russian occupation since it was illegally annexed, and any move to recognize Moscow’s control of the peninsula would reverse around a decade of US policy.

The US proposal – which has also been submitted to Moscow – would also put a ceasefire in place along the front lines of the conflict, the source said.

US Secretary of State Marco Rubio warned Friday that the US was ready to “move on” from efforts to bring peace to Ukraine within days if there were no tangible signs of progress.

US President Donald Trump has offered more optimism, saying in a Truth Social post on Sunday that “hopefully” Russia and Ukraine “would make a deal this week.” He didn’t specify what type of deal might be agreed.

Trump has declined to say whether he is prepared to walk away completely from the talks or whether the US would support Ukraine militarily if talks fall through.

The source that spoke to CNN on Friday said there are still pieces of the framework to be filled out, adding that the US plans to work with the Europeans and the Ukrainians on that in London this week.

The Trump administration is simultaneously planning another meeting between US Middle East envoy Steve Witkoff and the Russians to get Moscow on board with the framework, the source said.

There has been no comment so far from Kyiv or Moscow on the US proposal.

Ukrainian President Volodymyr Zelensky has expressed willingness to agree to a peace deal with Moscow but said last month that his government would not recognize any occupied territories as Russian, calling that a “red line.”

Easter truce expires

Both sides accused each other of violating the 30-hour Easter truce, which was announced unexpectedly by Putin to immediate Ukrainian skepticism on Saturday.

Zelensky on Sunday accused Russian forces of breaching the ceasefire nearly 3,000 times since the start of the day. The Ukrainian president had called for the ceasefire to be extended to 30 days, in line with a US-led proposal last month that Russia rejected.

Russia’s Ministry of Defense claimed on Sunday it had observed the ceasefire since it came into effect and accused Ukraine of breaching it more than 1,000 times. On Monday morning, Putin claimed an even higher figure, alleging that Ukraine had broken the ceasefire “almost five thousand” times.

Putin earlier said the truce was on humanitarian grounds but added that his troops would respond to any “provocations.”

Ukraine’s Armed Forces said they would comply with orders to limit fire on Russia’s army, but would not show restraint if fired on first.

There have been no pauses in fighting since Russia launched its unprovoked full-scale invasion of Ukraine in 2022.

CNN’s Ross Adkin, Victoria Butenko and Kylie Atwood contributed reporting.