Chinese rescue teams say it might be more than two weeks until they can save a group of miners trapped hundreds of metres underground.

Authorities made contact with 11 surviving miners a week after the blast, but one has since died.

The cause of the explosion that sealed the mine entrance is still not known.

The fate of another 11 miners trapped by the blast is unclear - authorities have been unable to communicate with them despite lowering food and messages into other areas of the mine.

The entry into the mine was severely damaged and communication was cut off by the so-far unexplained explosion.

A paper note was then sent up on a rope from a group of 12 surviving miners - 11 trapped in one place and a 12th trapped further below.

Since then, the contact with the 12th miner has been lost, while one of the group of 11, who had fallen into a coma after sustaining a head wound in the explosion, was on Thursday confirmed dead.

In December last year, 23 miners died after a carbon monoxide leak at a coal mine.

In December 2019, an explosion at a coal mine in Guizhou province, south-west China, killed at least 14 people.

The group of 10 known survivors are trapped in the dark some 600m (2,000ft) underground.

Chinese coal miners killed by carbon monoxide poisoning?