At least two people were injured in a handgrenade attack on a NATO oil tank in Pakistan's southwest city of Chaman which borders Afghanistan, local media reported on Wednesday morning.

No further details are immediately available about the attack.

NATO convoy transporting goods from Pakistan to NATO troops in Afghanistan are frequently attacked by militants. On May 28 over 60 NATO supply trucks, mostly oil tankers, were destroyed by militants and eight people were killed in the attack.

The frequent attacks on NATO convoy have forced NATO to decide in mid-June to open another route into the landlocked Afghanistan from the north via central Asian countries. But the new planned route is both time-consuming and costly due to terrain and weather conditions.

So far Pakistan remains the most shortest way for NATO to supply goods for its troops fighting Taliban militants in Afghanistan. It is reported over 70 percent of the goods needed by NATO troops in Afghanistan are sent through the land route in Pakistan.

The reported smuggling of illegal goods such as wine under the name of NATO supplies could also be a factor contributing to the attacks on NATO convoy in Pakistan.