Four more men trapped in a semi-submerged Laos cave for 10 days have been freed, rescuers said, after one was successfully brought to the surface a day earlier, but two remained missing.

"4 victim is out," Lee Kian Lie, a Malaysian rescue diver, told AFP via Messenger.

"Water level is lowered by pumping, so they able to come out," he said.

The Thailand Rescue Diver Facebook page said in a post that "rescue officials were able to bring out four more people trapped" at about 3:10 pm (0810 GMT) today.

"A total of five people have now been rescued, while two remain missing," it said.

Seven men had been trapped in the cavern in a remote mountainous area of central Xaysomboun province since May 20, when flash floods stranded them as they searched for gold, state media reports said.

Five of the men were located alive on Wednesday, huddling in a narrow shaft around 300 metres (984 feet) from the cave mouth.

Rescuers guided a bedraggled and muddy man over unsteady ground to safety on Friday.

The seven were trapped after heavy rains triggered flash flooding that blocked the exit of the cavern.