A prisoner exchange is under way between Russia and Ukraine, governments in Moscow and Kyiv have confirmed.

Ukraine’s President Volodymyr Zelensky said the exchange would unfold “in several stages” over the coming days, adding that the wounded, seriously wounded and soldiers under 25 were being returned.

Writing on Telegram, Zelensky said: “The process is quite complicated, there are many sensitive details, negotiations continue virtually every day.”

Russia said a “similar number” of prisoners of war had been returned to Ukraine, though neither side provided an exact figure for how many people had been exchanged.

Russia’s defence ministry said “the first group of Russian servicemen under the age of 25 were returned from the territory controlled by the Kyiv regime” following an agreement reached between the warring countries last week during talks in Turkey.

As with past exchanges, Moscow said the exchanged Russian soldiers were receiving psychological and medical assistance in Belarus.

On the Ukrainian side, relatives of prisoners of war and the missing gathered in the Chernihiv region, close to the border with Belarus, to greet the released prisoners and, in many cases, seek news of others still in captivity.

Last week, Moscow and Kyiv accused each other of disrupting the planned repatriation of the bodies of dead soldiers.

In late May, Russia and Ukraine each handed over 390 soldiers and civilians in the biggest prisoner exchange since Russia launched the full-scale invasion in 2022.

Meanwhile, war continued overnight, with Moscow launching a record 479 drones at Ukraine, including on the western region of Rivne that had been largely spared from attacks.

Russia’s defence ministry said it had targeted Rivne’s Dubno base and described this as “one of the retaliatory strikes” in response to Ukraine’s audacious drone attacks on Russian airfields on 1 June.

The overnight Russian launches caused damage in several Ukrainian regions but there were no reports of casualties.

Russia has recently escalated its attacks on Ukraine, with each week bringing a new record of drones fired at the country.

For its part, Kyiv said it attacked another Russian airbase in the Nizhny Novgorod region, which lies 400 miles from the Ukrainian border.

Ukraine said the base houses planes that launch hypersonic missiles and that it had damaged “two units of enemy aircraft”.

It also targeted an electronics factory that Kyiv says manufactures equipment to guide drones and aerial bombs.

Video shows one of the explosions caused by an attack drone, and a large fire at the plant. Production there has been suspended.