QUETTA: Suspected militants on Thursday opened fire on three tankers in Balochistan's Mastung district, police said.

Amir Hamza, a police official told Dawn that four gunmen on two motorcycles opened fire at the tankers carrying fuel for Nato troops deployed in Afghanistan near Mastung bazaar. He said one tanker caught fire, whereas drivers of the other two tankers sped away.

"The militants escaped on their motorcycles after the attack," Hamza said.

Roaring flames of fire and thick black smoke could be seen from quite a distance, he said, adding that the tankers were en route to Afghanistan from Karachi's Port Qasim when the attack took place.

Frontier Corps and police rushed towards the spot and cordoned off the area to probe the incident.

There was no immediate claim of responsibility for the attack on the vehicles carrying Nato supplies.

Militants have been targeting Nato supplies in Mastung, Bolan, Khuzdar and Quetta.