Efforts are being made in Zimbabwe to bring trapped illegal miners to the surface, after a shaft collapsed at a gold mine killing at least two other miners.

The BBC's Shingai Nyoka reports that the national disaster management agency has rescued two miners from the site in the town of Kwekwe who are now in hospital being treated for their injuries.

On Thursday it was thought that 20 people were trapped underground but the government now says it's not sure how many people remain trapped because some could have found their way out through other tunnels within the disused mine.

The Globe and Phoenix mine had been in operation since the 1800s but was closed down over a decade ago because it was deemed environmentally unsafe.

BBC correspondents say there are reports this latest accident may have been caused by rockfall, though this has not been confirmed.

Mining is a major source of foreign currency in Zimbabwe, which has vast gold and mineral reserves including diamonds and platinum.

But mining is largely unregulated, leading to many accidents. Twenty-two miners were killed nearby a year ago.