Russia-Ukraine updates: Putin suspends key US-Russia nuclear treaty in speech denouncing West

Thirty-three missiles were fired at Ukraine on Saturday morning, 18 of which were shot down, the country's air force claimed. Local officials in regions across Ukraine are reporting that the strikes were aimed at energy facilities.

More than a million people were without power as of Saturday afternoon, according to presidential adviser Kyrylo Tymoshenko.

In the southeastern city of Nikopol, local authorities warned that air raid sirens would be switched off as a result of power cuts. Instead, emergency vehicles driving around the city will warn resident of incoming aerial threats.

-ABC News' Jason Volack

Russian authorities in the Ukrainian city of Kherson told civilians to leave immediately on Saturday because of what they called a tense military situation as Ukrainian forces advance. Kherson was illegally annexed by Russia earlier this month.

"Take care of the safety of your family and friends! Do not forget documents, money, valuables and clothes," Russian authorities said.

At Oleshky on the opposite bank of the Dnipro, the agencies caught up with people arriving by river boat from Kherson, loaded with boxes, bags and pets, according to an article in Russian News Agency Interfax.

One woman carried a toddler under one arm and a dog under the other. Some boats were loaded with vegetables and pallets of food. Staff from Russia's emergency ministry carried elderly people and children in prams from the vessels. Families then waited to board buses to the Russian-annexed city of Crimea, according to Interfax.

Meanwhile, in a briefing on Saturday, the Russian Defense Ministry said its forces had repelled a Ukrainian attempt to break through its line of control in the Kherson region.

-ABC News' Jason Volack and Anastasia Bagaeva

Russia is deliberately delaying the passage of ships carrying grain exports under a U.N.-brokered deal, Ukrainian President Volodymyr Zelenskyy alleged in his evening address Friday.

Zelenskyy said the delay meant that Ukraine grain exports were short 3 million tons, which he said is enough to feed 10 million people.

"The enemy is doing everything to slow down our food exports ... as of today, more than 150 ships are queuing to fulfill contractual obligations on the delivery of our agricultural products," Zelenskyy said.

"This is an artificial queue. It only arose because Russia is deliberately delaying the passage of the ships," he said.

-ABC News' Jason Volack

Russian attacks have hit 30% to 40% of Ukraine's overall national power infrastructure, Ukraine's Energy Minister Herman Halushchenko told Reuters in an interview.

"We see that they targeted a number of new [facilities], but also they shelled [facilities] which had been already shelled before to destroy them absolutely," Halushchenko said.

Asked about the scale of the damage, Halushchenko said Russian attacks have hit at least half of Ukraine's thermal generation capacity and caused billions of dollars worth of damage.

Halushchenko said electricity imports could be one of the options Ukraine pursues to get through the crisis.

-ABC News' Jason Volack