KYIV, Ukraine (AP) — Russian drone and missile strikes on the Ukrainian city of Dnipro killed at least four people and wounded 21, local authorities said Saturday.

The bodies of the four were found in the ruins of a house destroyed in the overnight attacks, Dnipropetrovsk regional head Oleksandr Ganzha said.

Ukrainian President Volodymyr Zelenskyy said Saturday that there were “11 people in hospitals in Dnipro after the Russian attack on the city.”

“The Russians have been hitting Dnipro and other cities and communities practically all night,” Ganzha wrote on Telegram of the attacks, which caused fires to break out across Dnipro and partially destroyed several apartment buildings, businesses and a private house.

To the southwest, two people were wounded in overnight drone attacks on the Odesa region.

Residential buildings, port infrastructure and cars were damaged in the south of the region, regional head Oleh Kiper said Saturday.

In Russia, a woman was killed and a man was seriously wounded by a drone strike in the border region of Belgorod, local officials said.

Following the overnight attacks, Romania’s defense ministry said Saturday that drone fragments were found in a residential area of the southeastern city of Galati, near the NATO member’s border with Ukraine. No casualties were reported.

Romania has confirmed drone fragments on its territory on multiple occasions.

The overnight attacks followed a prisoner swap Friday, in which Russia and Ukraine exchanged 193 service members.

Periodic prisoner exchanges have been one of the few positive outcomes of otherwise fruitless monthslong U.S.-brokered negotiations between Moscow and Kyiv. The talks have delivered no progress on key issues preventing an end to Russia’s invasion of its neighbor, now in its fifth year.