Ukrainian soldiers were welcomed home by their families in a prisoner swap with Russia that marked a rare moment of cooperation between the two countries.

The exchange, however, came just hours after Vladimir Putin's army launched a large-scale drone and missile attack on Kyiv that left at least 15 people injured.

President Volodymyr Zelensky and Russia's defense ministry said each side released 307 soldiers on Saturday, a day after each also freed 390 prisoners.

Further releases expected over the weekend are set to make the swap the largest in more than three years of war.

'We expect more to come tomorrow,' Zelenskyy said on his official Telegram channel.