DHAKA: At least two people are thought to be missing after an explosion sent flames tearing through a Manhattan building.

The blast, the result of faulty utility work, caused three buildings to collapse on Thursday, injuring 22 people, four critically, reports BBC.

Officials are trying to determine whether one other person who has been reported missing is connected to the incident.

As the fire is contained, families are desperately searching for loved ones.

Fire fighters and medical staff worked overnight to try and douse the flames in Manhattan's East Village.

Nicholas Figueroa, 23, was on a date at a sushi restaurant affected by the explosion and has not been seen since, his brother Tyler said.

His date, who lies in hospital, remembers only stumbling out of the restaurant before losing consciousness.

"I just pray my brother shows up," said Tyler Figueroa.

Authorities are also looking for Moises Lucon, a worker in one of the buildings.

Earlier, officials said they were investigating the cases of six other people who had been reported missing - besides Figueroa and Lucon. The people were all unaccounted for, but their connections to the incident were not clear.

Officials now say that they are only investigating the disappearance of one other person.

Fire fighters spent Friday pouring water on the crumbled wreckage that remained strewn across parked cars and surrounding streets.

Officials said early indications are that the explosion was caused by shoddy plumbing and gas work inside one of the buildings.

Utility inspectors declared the work faulty just an hour before the blast tore through a restaurant that occupied the ground floor and sparked a fire that continues to burn.

Blake Farber, a witness, said he had been walking by the building and smelled gas seconds before the big blast.

BDST: 0946 HRS, MAR 28, 2015