Police say suspected militants have attacked and set on fire at least 20 oil tankers in Pakistan that were en route to NATO and US troops in Afghanistan The attack early Monday close to the capital Islamabad was the third since Friday, according to AP. One of the main routes used by Afghanistan-bound trucks has been closed for days after three Pakistani troops were killed in a helicopter strike by the military alliance in a border area. Police officer Umer Hayat says two people were killed in Monday's attack.