A powerful blast ripped through a busy commercial area in Peshawar on Saturday killing three people and injuring 14 others, as officials said it appeared to be an accidental explosion and it was yet to be determined if the incident was a terrorist attack.
The blast occurred at a building on University Road shortly after 11.30 am, sparking a massive fire.
Officials and local residents said a woman was among three people killed by the explosion.
The 14 injured people were taken to nearby hospitals.
There was confusion about the nature of the blast. District administration chief Shahibzada Anees initially said it appeared that the explosion was caused by a bomb planted in a car parked outside the building.
Witnesses said they had seen a car parked outside the building. Some persons even made inquiries about the car after they were unable to trace its owner.
However, Peshawar police chief Liaquat Ali Khan and Shafqat Malik, chief of the city's bomb disposal squad, said investigators had found no trace of explosive materials at the site.
Malik said it appeared that the incident was caused by an accidental explosion of paints and chemicals stored in a shop.
The three-storey building had several shops, commercial establishments and private offices.
A part of the building was destroyed and local residents used ladders and ropes to help people trapped on upper floors to escape. The blast also smashed windows of nearby shops and residential buildings.
Several cars parked on the road were gutted by the fire. Thick black smoke billowed out of the building as fire fighters battled the blaze.
Nearby roads were blocked for traffic and security personnel cordoned off the area for some time.
The blast came a day after a group of militants stormed a mosque frequented by military officers in the garrison city of Rawalpindi, killing 40 people, including a major general and several other senior army officers.
Peshawar has witnessed a series of bombings and suicide attacks targeting public places and security facilities over the past two months.
The Taliban have been blamed for these attacks, which began after the army launched operations against militants in South Waziristan tribal region.Hundreds have died in these attacks.