A gas explosion in a coal mine in Iran's South Khorasan Province killed at least 51 people and injured 20, Iran's state media said on Sunday.
The accident was caused by a methane gas explosion in two blocks, B and C, of the mine run by the Madanjoo company, state media said.
"76% of the country's coal is provided from this region, and around 8 to 10 big companies are working in the region, including Madanjoo company," the governor of South Khorasan Province, Ali Akbar Rahimi, told state TV on Sunday.
The rescue operation in block B has been completed. Of the 47 workers who were in the block, 30 died, and 17 were injured, Rahimi said earlier.
Rescue operations in block C have started. The block's methane density is high, and the operation will take 3-4 hours, he added.