By MOGOMOTSI MAGOME and GERALD IMRAY (Associated Press)

JOHANNESBURG (AP) — At least 16 people, including three children, died when toxic gas leaked from a cyclinder near Johannesburg, South African police said Wednesday.

Emergency services said that as many as 24 people might be dead. It wasn’t immediately clear why there was a discrepancy in the death toll.

Search and rescue teams were still working through the area trying to ascertain the extent of the casualties.

The incident happened in an informal settlement in the city of Boksburg on the eastern outskirts of Johannesburg, the South African Police Services said.

Emergency services spokesman William Ntladi said the deaths were caused by a leak from a gas cylinder being kept in a shack in the Angelo settlement. He said the leak had stopped and teams were searching a 100-meter (100-yard) radius around the cyclinder to check for more casualties.

The bodies were still lying on the ground “in and around the area,” Ntladi said, and forensic investigators and pathologists were on their way to the scene.

“We can’t move anybody,” Ntladi said. “The bodies are still where they are on the ground.”

Police said the three children killed were aged 1, 6 and 15. Two people were taken to the hospital for treatment, police said.

Boksburg is the city where 41 people died after a truck carrying liquified petroleum gas got stuck under a bridge and exploded on Christmas Eve.

Ntladi said the initial information authorities had indicated the gas in the cylinder was being used by illegal miners to process gold inside a shack. He did not identify the type gas.

Illegal mining is rife in the gold-rich areas around Johannesburg, where miners go into closed off and disused mines to search for any deposits left over.

Imray reported from Cape Town, South Africa.