Unidentified gunmen in Pakistan\'s southwestern Balochistan province on Monday attcked tankers, carrying oil for NATO troops in Afghanistan, witnesses said. At least 10 oil tankers were burnt in the attack, they said. The attackers fled after the incident and no group claimed responsibility. There was no report of any casualty. The oil tankers were heading to Afghanistan from the port city of Karachi when came under attack at Dasht area in Balochistan. Witnesses said the gunmen first opened fire and then burnt the tankers. Suspected militants routinely target NATO supplies trucks and oil tankers mostly in Pakistan\'s northwest and attacks in Balochistan are rare. Officials say that about 70 percent supplies for upto 160,000 US-led NATO troops are transported through Pakistan. The United States has signed deal with Russia for alternate supply route in view of frequent attacks on NATO trucks in Pakistan.