More than 60 workers were killed when an unlicenced desert gold mine collapsed in an area of Sudan's Darfur where hundreds died in fighting over the precious commodity in January-February, the district chief said Thursday.
It was not known how many people may still be missing after Monday's accident in Jebel Amir district, more than 200 kilometres (125 miles) northwest of the North Darfur state capital El Fasher.
Production from unofficial gold mines has become a key revenue source for Sudan's cash-strapped government.
It is also a tempting but dangerous occupation for residents of Sudan's poverty-stricken western region of Darfur which has been devastated by a decade of civil war.
"The number of people who died is more than 60," said Haroun al-Hassan, local commissioner for Jebel Amir, adding that rescue operations were still taking place.
"I cannot give exact figures because no one got precise numbers of how many people were going inside the tunnel," which descends 40 metres (yards), he said.
Rescuers were using hand tools to try to reach the victims, he said, without specifying whether anyone might still be alive.
"We cannot use machines because if they came near, the ground will collapse. People are using traditional tools and because of this, the rescue is very slow," Hassan said, unable to give more details.
"I myself saw this land collapse. It started from Monday evening but the main collapse happened on Tuesday," said a miner who works in a different part of the area.
He said it is located in the hill or "jebel" which gives the area its name.
"Nobody takes the names of those who go inside. Only their colleagues or their relatives know where they are," the miner said, requesting anonymity.
They risk their lives, maybe striking gold but often coming up empty.
"Sometimes you spend more than three or four weeks without getting anything," the miner said. "Other times you get gold that you can sell for 10,000 pounds ($1,590)".
A resident of El Sireaf, the main town in the surrounding region, said he visited the remote site of the accident.
"The problem is that those small mines are so close together and if one of them falls it will affect the others. That is what happened in this mine. All the neighbouring mines collapsed," he said, also declining to be named.
Residents and members of the security forces were using hand tools to reach the victims, he added.
A humanitarian source said earlier this year that close to 70,000 people were digging for gold in Jebel Amir.
Sudan is trying to boost exports of the rare metal and other non-petroleum products after the separation of South Sudan two years ago left Khartoum without three-quarters of its crude oil production.
The lost oil accounted for most of Khartoum's export earnings and half of its fiscal revenues, sending inflation above 40 percent while the currency plunged in value on the black market.
Sudan's Mining Minister Kamal Abdel Latif said traditional mining produced 41 tonnes of gold worth $2.5 billion from January to November last year.
In 2011, the government estimated there were more than 200,000 unlicenced artisanal gold producers, generating most of the country's output of the metal.
Sudan's central bank has entered the market, trying to buy from the small producers.
Seven weeks of clashes between two Arab tribes in Jebel Amir early this year killed more than 500 members of the Beni Hussein tribal group, a Benni Hussein member of parliament for the area said previously.
The violence uprooted an estimated 100,000 people.
The fighting between the Beni Hussein and Rezeigat erupted when a leader of the latter tribe who is a border guard officer apparently laid claim to a gold-rich area inside Beni Hussein territory, Amnesty International said.
Beni Hussein refused to pay newly-imposed government mining fees which amounted to "huge, huge money", the humanitarian source said.