Russian 'suicide drones' strike terror in Ukraine, US warns on war crimes

Russia attacked Ukraine with drones late on Monday, Ukrainian President Volodymyr Zelenskiy said, after a day of strikes on cities in which at least four people were killed and a US warning that it will hold Russia accountable for war crimes.

Russian forces also targeted infrastructure across Ukraine in the second wave of air strikes in a week, which like the first came in the morning as people went to work and school.

The Russian strikes followed advances by Ukrainian forces in the east and south and after an October 8 blast on a bridge linking mainland Russia to Crimea - the peninsula Russia annexed from Ukraine in 2014.

"Right now, there is a new Russian drone attack," Zelenskiy, said in a Monday evening video address. "There are (drones) that have been shot down."

The Interfax Ukraine news agency said Telegram users had reported blasts in the town of Fastiv just outside Kyiv, as well as in the southern port of Odesa.

Earlier on Monday, Ukrainian soldiers fired into the air trying to shoot down drones, and as residents raced for shelter, after blasts rocked the capital Kyiv.

US President Joe Biden's press secretary Karine Jean-Pierre told reporters that the White House "strongly condemns Russia’s missile strikes" and said the attack "continues to demonstrate Putin’s brutality".

Russian President Valdimir Putin sent tens of thousands of troops into Ukraine on February 24 in what he called a "special operation" to root out what it calls dangerous nationalists.

Ukrainian forces have mounted stiff resistance, with the help of arms supplied by the United States and its allies, who have also imposed sweeping sanctions on Russia in an effort to force it to withdraw.

Mentioning a $725 million military aid package announced for Ukraine last Friday, Jean-Pierre said the United States would stand with the people of Ukraine "for as long as it takes".

"We will continue to impose costs on Russia, hold them accountable for its war crimes," she said.

Ukraine's Interior Minister Denys Monastyrskyi said there had been deaths in other cities but did not provide a full toll.

Black smoke poured out of the windows of the Kyiv apartment building and emergency service workers toiled to douse flames.

Russia denies targeting civilians. Its defence ministry said it had carried out a "massive" attack on military targets and energy infrastructure across Ukraine using high-precision weapons.