A large Russian drone and missile barrage pummeled a western Ukrainian city, killing 20 people, including two children, authorities said Wednesday, as Ukrainian President Volodymyr Zelenskyy arrived in Turkey in search of diplomatic support for his fight against Russia’s invasion.

The nighttime attack hit two nine-story apartment blocks in Ternopil, located around 200 kilometers (120 miles) from the Polish border, according to Interior Minister Ihor Klymenko.

Emergency crews were sifting through the rubble in daylight to find any survivors, he said.

At least 66 people, including 16 children, were injured, emergency services said.

Russia fired 476 strike and decoy drones, as well as 48 missiles of various types, at Ukrainian targets overnight, Ukraine’s air force said.

The bombardment included 47 cruise missiles, with air defenses intercepting all but six of them, the air force said.

Western-supplied F-16 and Mirage-2000 jets intercepted at least 10 cruise missiles, it said.

The Ukrainian city of Ternopil sits in a part of relatively peaceful western Ukraine, where many people from the east and south moved to as they fled danger along the front line.

Almost 50 people were injured in Russian strikes on three other Ukrainian regions.

Russia’s Defense Ministry said it attacked Ukrainian energy facilities and military-industrial targets, including long-range drone depots, in retaliation against strikes by Kyiv on Russian territory.

“Every brazen attack against ordinary life indicates that the pressure on Russia (to stop the war) is insufficient,” Zelenskyy wrote on the messaging app Telegram.

The Ukrainian leader said he would meet with Turkey’s President Recep Tayyip Erdogan later Wednesday as part of his efforts to diplomatically isolate Russian President Vladimir Putin and bring more international pressure to bear on him.

Putin has so far resisted making compromises, despite U.S. pressure.

Tough new American sanctions on Russia’s oil industry, devised to push Putin to the negotiating table, are due to take effect on Friday.