Picture used for illustrative purposes.

A gas leak in a coal mine in Pakistan's southwestern province of Balochistan on Monday killed 11 people, nine of them miners, an official said.

"The deaths occurred due to asphyxiation after a gas leak," Abdul Ghani Baloch, head of the provincial government's mining department, told AFP, adding that a contractor and a mine manager were also among the dead.

The mine -- operated by United Coal Company, a private firm -- is located 40 kilometres (25 miles) from the provincial capital Quetta.

In March, 12 miners were killed in the same province in a gas explosion that caused the mine to cave in.

Balochistan is Pakistan's largest but poorest province, and is rich in natural resources, which locals have long bemoaned are not shared fairly among their communities.

Agence France-Presse