Moscow (AFP) - The death toll from a Ukrainian strike on a college in a Russian-occupied town in eastern Ukraine rose to 18, Russian officials said Saturday, as Kyiv warned it was expecting a major Russian missile attack.

Launched overnight on Thursday to Friday, one of the deadliest Ukrainian drone barrages in months also wounded 42 in Starobilsk, in the occupied Lugansk region, with some still trapped under the debris.

Ukraine had denied targeting civilians, insisting it had hit a Russian drone unit stationed in the Starobilsk area. But President Vladimir Putin has ordered the army to prepare a response.

“Two more bodies have been recovered from under the rubble,” Russia’s emergency ministry said Saturday. “In total: 60 victims, of whom 18 have died.”

Video shared by the ministry showed dozens of rescuers sifting through what remained of a section of the five-storey dormitory building, now reduced to rubble.

Most of those killed and missing were young women born between 2003 and 2008, according to a list of casualties published by the Moscow-backed governor of the Lugansk region, Leonid Pasechnik.

“The region and the entire country share the fate of these people and the pain of their families,” he said on Telegram.

In Russia and on the occupied territories of Ukraine, a college is an equivalent of a vocational school, typically for students aged from 15 to 22 years.

Starobilsk lies about 65 kilometres (40 miles) from the front line in eastern Ukraine. It was captured by Russian forces in the early months of the offensive in 2022.

The Lugansk region is almost entirely occupied by Russia, which claims it as its own.

- ‘Severe punishment’ -

The UN said on Friday it “strongly condemns any attacks against civilians and civilian infrastructure, wherever they occur”, adding it couldn’t verify details due to restricted access to the area.

Russia’s foreign ministry said on Friday that those responsible would face “inevitable and severe punishment”.

And on Saturday both Ukrainian President Volodymyr Zelensky and the US embassy in Kyiv issued warnings about the risk of a major Russian airstrike in the coming hours.

“We are seeing signs of preparation for a combined strike on Ukrainian territory, including Kyiv, involving various types of weaponry” – including the Oreshnik, a Russian nuclear-capable missile – Zelensky said in a post on social media.

The US embassy in Kyiv said in a message posted on its website that it had “received information concerning a potentially significant air attack that may occur at any time over the next 24 hours”.

Zelensky, in an appeal to the international community, said: “Pressure must be put on Moscow so that it does not expand the war.”

- Drone warfare increasing -

Ukraine regularly targets Russian-controlled areas of the country with drones, saying the strikes are retaliation for Russian attacks.

Kyiv has recently expanded its drone capabilities and stepped up strikes on conventional Russian territories as well, including residential areas and oil export infrastructure.

Moscow has launched mass barrages of missiles and drones at Ukraine almost daily since the full-scale offensive began in 2022, also hitting infrastructure and causing civilian deaths.

Both countries deny targeting civilians.

The United Nations Human Rights Monitoring Mission in Ukraine has recorded more than 60,000 civilian casualties since 2022, almost 90 percent of which were in areas controlled by Ukraine.

The conflict, the bloodiest in Europe since World War II, has devastated swathes of land in eastern Ukraine and forced millions to flee.

US-led shuttle diplomacy aimed at brokering trilateral talks to end the war has stalled amid the Middle East conflict.