At least 15 people were killed Saturday in the explosion of a NATO oil tanker in Pakistan's north-western tribal areas along the Afghan border, officials said. The incident occurred around 1.30 am (2030 GMT Friday) in the Landi Kotal area of Khyber tribal district through which NATO supplies pass into Afghanistan. Khan Pasand, an official from the district administrator's office, told the German Press Agency 'DPA' by phone that the explosion occurred when people were collecting oil from an Afghanistan-bound tanker. He said oil began to spill when the tanker was damaged due to small blast in the night that caused a fire. Fire engines attended to extinguish it. "The second explosion occurred when locals had gathered to collect oil and it killed 15 of them and injured three others," Pasand said.