"Four bodies have been recovered so far" and five others are still stuck under rubble, Henrietta Rushwaya, president of the Zimbabwe Miners Federation, told AFP.
Mine engineer Hussein Phiri confirmed to AFP that rescuers had located the bodies of the five miners stuck under the rubble.
"We can clearly see (five) bodies," he told AFP. "We are convinced all of them are dead.
"It is however difficult to retrieve the bodies because the mine is still collapsing. Each time we try is becoming a threat to our lives as well."
The accident occurred on Friday in Chegutu, about 120 kilometres (75 miles) west of the capital Harare, state television ZBC said, at the Bay Horse Mine.
The Southern African country's Minister of Mines, Soda Zhemu, who had come to oversee the rescue efforts, confirmed that 21 miners had escaped.
On Friday morning, "immediately after the collapse, 13 people managed to get out of the mine unharmed", the minister said.
"During the night, eight others were rescued." 'Heartbroken'
The minister and the engineer also reported that three other miners were thought to be missing, but their whereabouts were unknown.
On Saturday afternoon, several hundred local residents watched in anguish as rescue workers tried to retrieve bodies from the mine.
Women wept as they waited for their husbands or sons to be pulled from the rubble.
"I'm heartbroken," said Vimbai Muchena, 38, whose son was trapped underground.
Johannes Nyautete, 33, was among the miners who escaped the mine.
"The mine started collapsing as soon as I landed on the underground tunnel which starts about 250 metres from the ground. It was around 10am on Friday," he said.
"We then saw some of our colleagues rushing out of the tunnel and we escaped together.
"It was a traumatising experience."
He said the mine collapsed because there were no safety pillars.
Earlier reports from ZBC had suggested that as many as 18 people could be buried underground.
But Rushwaya said that "at the time of collapse, 13 people were pushed out, alive... and another eight were rescued alive."
The southern African nation has vast reserves of platinum, diamonds, gold, coal and copper. Due to the floundering economy, illegal mining is rife and often takes place under dangerous conditions.
Accidents are common. In February 2019, 24 miners died when an abandoned pit flooded after torrential rains in central Zimbabwe.
