A gas explosion in a coal mine in Iran’s South Khorasan Province killed at least 51 people and injured 20, according to Iran’s state media on Sunday.

The blast was triggered by methane gas in two sections of the mine, called blocks B and C, which is operated by the Madanjoo company.

Governor Ali Akbar Rahimi said that the region provides 76% of Iran’s coal and has 8 to 10 large companies, including Madanjoo, working there.

The rescue in block B is done. Of the 47 workers inside, 30 died and 17 were injured, Rahimi said earlier.

Rescue operations in block C are still ongoing. Due to high methane levels, the operation is expected to take 3-4 more hours, he added.

In total, there were 69 workers in the two blocks when the explosion happened, according to state TV.

Earlier, the Iranian Red Crescent reported that 17 injured people were sent to the hospital, and 24 workers are still missing.

The explosion happened around 9 p.m. (1730 GMT) on Saturday, state media said.

President Masoud Pezeshkian expressed sympathy for the victims’ families and said he has spoken with ministers to ensure the situation is addressed.