Kyiv came under a large-scale Russian drone and missile attack early on Saturday morning.

Blasts and machine gun fire were heard across the Ukrainian capital, forcing many residents to take shelter in subway stations.

Kyiv Mayor Vitali Klitschko said two residents had required hospital treatment, and air defense units had been deployed to fend off the attack.

'Air defenses activated,' says Kyiv Mayor Klitschko

"Explosions in the capital," Klitschko wrote on Telegram. "Air defenses have been activated. The city and the region are under a combined enemy attack."

Klitschko said fragments from one drone hit the top floor of an apartment block in the Solomyanskyi district of the Ukrainian capital. One apartment block was ablaze in the area as was one non-residential building.

At least eight people were wounded in the "massive" attack, Klitschko said.

The head of the capital's civil and military administration, Tymur Tkachenko, reported two blazes in the Sviatochynskyi district, missile debris falling in the Obolonskyi district, and drone debris falling on a residential building in the Solomianskyi area, which lies in the city's west.

On Friday, Russian missiles killed two people and wounded several others in the Ukrainian port city of Odesa, according to authorities.

Moscow's military said Ukraine had targeted it with 788 drones and missiles since Tuesday, 776 of which had been shot down.

Attack comes shortly after prisoner swap

Saturday's early morning attack came just hours after Ukrainian President Volodymyr Zelenskyy announced the return of 390 prisoners of war to Russia.

The Russian Defense Ministry also said that Moscow had returned 390 individuals in a prisoner swap. According to the ministry, each side released 270 soldiers and 120 civilians.

The prisoner swap is the first stage of the "1000-for-1000" exchange agreement reached during the Russian-Ukrainian talks in Istanbul, Zelenskyy wrote on X.

"On Saturday and Sunday, we expect the exchange to continue," he added.

After more than three years of fighting, both countries are holding thousands of prisoners of war. Russia is believed to hold the larger share, with an estimated 8,000 to 10,000 Ukrainian captives.

Edited by: Louis Oelofse