The 13 Ukrainian troops on Zmiiniy Island, or "Snake" Island, might still be alive after defying a Russian warship last week - after they were previously believed to have been killed, the Ukrainian government said.

"The SBGSU and the Armed Forces, like the whole of Ukraine, have received hope that all of Zmiiny's defenders are alive," the State Border Guard Service of Ukraine said in a Facebook post on Saturday, noting that Russian media claims the soldiers were captured, not killed.

The main source seems to be the Tass agency.