ISLAMABAD - At least 19 oil tankers were burnt when a NATO supply convoy came under attack Monday afternoon in Pakistan's southwest province of Balochistan, reported local Urdu TV channel Geo.

According to the report, the attack took place at about 2:30 pm when unknown gunmen opened fire at a NATO convoy on the Sibi-to- Quetta Highway in the Dasht area of Mastung, a district some 60 kilometers south of Balochistan's capital city Quetta.

The attackers fled the scene after they opened fire at the convoy and set the oil tankers on fire.

Huge fire from the oil tankers could be seen several kilometers away, said the report, adding that six fire brigades were called in from Quetta to put out the fire.

No casualties were reported in the attack.

No group has claimed responsibility for the attack.

Attacks on NATO supply convoys are frequently reported in Pakistan's northwest Khyber Pakhtunkhwa province and southwest Balochistan province as nearly 70 percent of the NATO supplies shipped into Afghanistan has to pass two border ports in Pakistan, namely the Chaman border port in Balochistan and the Torkham border port in Khyber Pakhtunkhwa.