Emergencies Ministry spokesman Viktor Beltsov said the last four climbers had safely reached camp at the foot of the Klyuchevskaya volcano and were "doing well".

The others were rescued in stages on Wednesday - though one mountaineer who was hit by falling rock died of his injuries.

Mr Beltsov said his body will be retrieved when the weather improves.

Correspondents say there has been local criticism of the Czechs, who set out to climb the 4,500-metre high volcano on Monday without a guide.

The volcanoes are popular destinations for climbers

Reports say night-time temperatures have been plunging well below zero, fresh snow has been falling, and the volcano is spewing smoke and ash in what could be a prelude to an eruption.

The Czechs began their climb on 4 August.

Five Russians from a local search-and-rescue service began climbing the volcano early on Wednesday to try to reach them.

They met one group of climbers descending the mountain, but four others remained trapped higher up.

The Klyuchevskaya volcano, on the remote Kamchatka peninsula, is active and suffers rockfalls, earthquakes and gas escapes.

But the 4,750-metre (15,700-foot) peak remains a popular destination for climbers, who try to reach the top to peer into the crater.

The alarm was raised by three members of the party who managed to get off the volcano and alert the emergency services.

Russian officials have criticised the 20-strong group for attempting to scale the volcano without the help of local guides.