Putin vows retaliation after deadly drone attack on Ukraine student dorm

Russian President Vladimir Putin has promised retaliation after accusing Ukraine of carrying out a deadly attack on a student dormitory in an occupied part of eastern Ukraine.

Six people were killed and 39 injured in the overnight strike in the town of Starobilsk, Luhansk region, Putin said. Another 15 people were missing.

Ukraine's military said it hit the headquarters of Russia's elite Rubicon drone military unit in Starobilsk. It did not say whether it was the same building as the one identified by Russia.

"There are no military facilities, intelligence service facilities, or related services in the vicinity," Putin said in Moscow.

"Therefore, there is absolutely no basis for claiming that the munitions struck the building as a result of our air defence or electronic warfare systems," he said at a reception in his Kremlin residence on Friday.

He ordered the Russian military to prepare its "proposals" on how to retaliate.

The Russian leader said the Ukrainian strike had been carried out in three waves using 16 drones.

Russia's state-run TV showed what it said was one of the injured students, identifying her as Diana Shovkun, aged 19.

She had head injuries after being hit by a collapsing concrete slab, the TV said report said.

No photos or videos of those who Moscow says were killed were shown.

Early on Saturday, Russian officials reported two people were injured after falling debris from drones triggered a fire at an oil depot in Russia's Black Sea port of Novorossiysk.

The general headquarters of the southern Krasnodar region said "several technical administrative buildings caught fire" and fragments of drones fell on a fuel terminal. Two people were injured and were being treated in hospital, the headquarters said. No deaths were reported.

The General Headquarters said drones had also damaged private homes in the port city of Anapa further north.

Late on Friday, Ukraine's military said its overnight strike targeted Rubicon's headquarters in Starobilsk. It accused fighters from the special drone unit of regularly striking civilians and civilian infrastructure in Ukraine.

The statement also said that Ukrainian forces "are causing damage to military infrastructure and facilities used for military purposes, strictly adhering to the norms of international humanitarian law, laws and customs of war".