An explosion at a fireworks warehouse in the Pakistani city of Karachi killed four people and injured more than 30 on Thursday, police said.
The warehouse and some nearby shops caught fire after the initial blast, which was followed by several smaller explosions, forcing residents to flee for safety.
"I thought several bombs had exploded," resident Aqib Khan told reporters.
The impact of the blast was strong enough to shatter glass in neighboring shops, peppering people in the street with shards of glass.
At least 34 injured people were admitted to hospitals, said police official Summaiya Tariq, adding that four of those died overnight.
Smoke billowed from a multi-story building as firefighters worked to put out a blaze, local news channels showed. There was no indication as to what caused the initial explosion.
Mass panic, people running for safety
Closed-circuit camera footage aired by local television channel Geo News showed people running for safety and motorists turning their vehicles around in haste.
The explosion came a day after intense monsoon rains flooded the city.
Karachi is Pakistan's financial capital and is home to more than 20 million people.