ISLAMABAD, Aug 26: At least four people were killed and 14 others were injured in a mysterious explosion on Tuesday night, police said.

Police sources told Dawn that the blast was caused by an explosive device.

Earlier, the police had described the incident as a gas cylinder blast, but a few minutes later they got suspicious and said the possibility of sabotage could not be ruled out.

The explosion hit the compound of the restaurant, in Model Town, where scores of people were taking meal.

The blast was so devastating that it severely damaged the restaurant, its furniture and a taxi parked nearby. It created a big crater.

The incident occurred in the compound of the restaurant while the gas pipeline was outside the compound. Officials of the gas company also rejected the notion that the blast had taken place in the pipeline.

There were some reports that a teenage boy carrying a shopping bag was seen loitering around the restaurant some moments before the blast.

Omer Wali, a cook, said he was cooking meal when the explosion occurred and he was not aware what caused the explosion. Nearly 15 to 20 people were taking meal when the explosion rocked the restaurant.