The death toll from a shaft collapse at a disused gold mine in Zimbabwe was expected to rise to 13, the country’s vice president said, according to state media.

State-run newspaper The Sunday Mail quoted Vice President Constantino Chiwenga as saying “we believe we have lost about 13” in the mine disaster, which happened on Friday in the gold-rich town of Chegutu, about 60 miles (100km) west of the capital Harare.

He said 21 out of 34 miners thought to be underground at the time of the collapse had been rescued. Eight had been confirmed dead, with three bodies removed from the mine and five located but not yet removed, Mr Chiwenga said. The remaining five people were presumed dead.

Mr Chiwenga was speaking on Saturday at a meeting of the ruling Zanu-PF party, The Sunday Mail reported.

He said the collapse had happened at a disused German-owned mine that had not been properly sealed off, allowing unofficial artisanal miners to find their way in to search for any deposits left over.

Incidents of mine collapses, often involving artisanal miners, are common in the southern African country that is rich in gold, coal and diamonds. Zimbabwe also has Africa’s largest reserves of lithium, a mineral in global demand due to its use in electric car batteries.

Zimbabwe’s mineral-rich national parks, abandoned mines, rivers and even towns are often swarmed with people, including young children, seeking to find valuable deposits. It is one of the few economic activities still going on in a country that has suffered industry closures, a currency crisis and high unemployment over the past two decades.

Critics blame economic mismanagement and corruption for the collapse of a once-thriving economy. The government points to two decades of sanctions imposed by the United States over allegations of human rights violations by the government.