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.
Putin said six people were killed and 39 injured in the overnight strike in the town of Starobilsk, in the Luhansk region, while 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 identified by Russia.
Putin said in Moscow there are no military facilities, intelligence service facilities, or related services in the vicinity.
He said there is absolutely no basis for claiming that ammunition struck the building as a result of air defence or electronic warfare systems.
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 19-year-old Diana Shovkun.
The TV report said she had head injuries after being hit by a collapsing concrete slab.
No photos or videos of those Moscow says were killed were shown.
Later 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 Ukrainian forces are causing damage to military infrastructure and facilities used for military purposes, strictly adhering to the norms of international humanitarian law, and the laws and customs of war.
Ukraine has repeatedly accused Russia's military of deliberately targeting civilians since the start of Moscow's full-scale invasion in 2022 — a charge Moscow regularly denies.
Source: BBC
