KYIV, Ukraine (AFP) — A massive Russian drone and missile attack on Kyiv Saturday wounded at least 15 people, just as Russia and Ukraine were in the middle of a major prisoner swap.

Ukraine’s air force said Russia had launched 14 ballistic missiles and 250 attack drones in total overnight, adding that Kyiv was “the main target of the enemy attack.”

Ukrainian Foreign Minister Andriy Sybiga said on X the barrage was “clear evidence that increased sanctions pressure on Moscow is necessary to accelerate the peace process.”

Kyiv city officials reported fires and fallen debris in several parts of the Ukrainian capital, after Agence France-Presse journalists heard explosions overnight.

The police said 15 people were injured in Kyiv and two more in the surrounding region.

Ukrainian presidential aide Andriy Yermak said Russia was “doing everything it can to prevent a ceasefire and continue the war.”

The Russian military meanwhile said Ukraine had targeted it with 788 drones and missiles since Tuesday.

The attack on Kyiv came hours after Russia and Ukraine completed the first stage of a prisoner exchange agreed at talks last week in Istanbul which, if completed, would be the biggest swap since the start of the conflict.

Both sides received 390 people in the first stage and are expected to exchange 1,000 each in total.

Russia has signalled it will send Ukraine its terms for a peace settlement after the swap, which is set to continue over the weekend — without saying what those terms would be.