At least 32 people were killed in a coal mine explosion in southwestern Pakistan on Thursday, as authorities continue search and rescue efforts to help workers trapped underground.

The blast was reportedly caused by a build-up of methane gas, a common hazard in underground coal mines, at a coal mine complex in Sorange, near Quetta, the capital of Balochistan province. 

The incident affected two adjacent mines, causing part of the mine to collapse and leaving dozens of workers trapped.

Pakistani authorities confirmed that 36 miners were working in the affected section when the blast happened, while over 40 workers were inside the mine complex at the time of the incident.

Emergency response teams went about 4,000 feet (1,219 metres) underground into the mine to search for survivors and recover the bodies of the victims.

Authorities also said the chances of finding survivors were very slim due to low oxygen levels after the explosion.

Pakistan’s Central Mines Labour Federation blamed the incident on negligence and called for stricter enforcement of mine safety regulations. 

Balochistan’s Minister for Mines and Minerals, Shoaib Nosherwani, expressed his condolences to those affected by the blast and announced that compensation of 500,000 Pakistani rupees would be given to each victim’s family.

Mr Nosherwani also promised a full investigation into the cause of the explosion. 

Pakistan has recorded several deadly accidents in its coal mining industry. Despite the dangers, many people continue to work in the mines due to the lack of employment opportunities.