Ukraine has accused Moscow of forcibly taking thousands of civilians from the shattered port city of Mariupol to Russia so they can be used as “hostages” to pressure Kyiv to give up.

Ukraine’s Foreign Ministry said that Russian forces have taken 6,000 Mariupol residents to camps against their will.

Russian troops are confiscating identity documents from an additional 15,000 people in a section of Mariupol under Russian control, the ministry said.

Ukrainian military intelligence said civilians are being sent through a camp in Russian-controlled territory, then onward through southern regions of Russia to economically depressed parts of the country.

Some could be sent as far as the Pacific Ocean island of Sakhalin, Ukrainian intelligence said, and are being offered jobs on condition they do not leave for two years.

Russia has said it is evacuating thousands of civilians of their own free will.

Meanwhile, Ukraine’s navy said it sank a large landing ship near the port city of Berdyansk that had been used to supply Russian forces with armoured vehicles.

Photos and video showed fire and thick plumes of smoke.

Russian TV reported earlier this week that the vessel the Ukrainians claimed to have sunk, the Orsk, was the first Russian warship to enter Berdyansk.

The port was going to be used to deliver military equipment for the Russians, the report said.

Ukraine claimed two more ships were damaged and a 3,000-tonne fuel tank was destroyed when the Orsk was sunk, causing a fire that spread to nearby ammunition supplies.