A massive fire ripped through a crowded shopping mall in Pakistan over the weekend, killing at least six people and injuring dozens more.

The blaze broke out around late Saturday night after emergency crews received calls reporting flames inside the building, according to Reuters. By the time first responders arrived, the situation had already spiraled out of control.

"When we arrived, the fire from the ground floor had spread to the upper floors, and almost the entire building was already engulfed in flames," a Rescue 122 spokesperson told Reuters.

Officials say the fire eventually destroyed more than 1,200 shops. Authorities have confirmed six deaths so far. At least 22 people were injured, including several firefighters.

Investigators believe the fire was sparked by a short circuit in one of the shops, according to Sindh Inspector General, adding the mall's old construction and the flammable materials sold inside caused the fire to continue smoldering for hours.

Emergency crews responded with 22 fire brigades and 33 ambulances, and officials said the fire was about 70% contained by Sunday morning.