By Bianca Tan (staff@latinospost.com) | First Posted: Jul 12, 2013 12:49 AM EDT

An explosion inside a hair salon in New York's Chinatown on Thursday left 12 people injured after the building ignited and partially collapsed.

Among the 12 injured are four firefighters, while three of the victims are reportedly in critical condition. Other injuries included burns.

According to the New York Daily News, the explosion happened around 12:45 in the afternoon at the Piao Liang Ren Scheng Beauty Salon in 17 Pike Street. A police source told the news website that improper use of pest fumigation items had caused the incident. Fire investigators found "boxes of Raid fumigating foggers and Decon bug bombs" at the back of the first-floor of the five-story building.

The source said the bug bombs were being "improperly used" when the explosion happened inside the Piao Liang Ren Scheng Beauty Salon, causing the fire and a minor ceiling collapse.

However, Fire Chief John Bley told CBS News that the cause of the fire is still uncertain. While the bug bombs might have aggravated the blaze, causing minor collapses in the ceilings of the building, the cause of the fire that was put out at around 1:30 p.m. is still in question.

Building residents said the explosion sounded like a bomb going off.

"[I heard] boom, like a bombing, like an earthquake," Tszkan Cheung told CBS, saying he was at his fourth-floor apartment eating lunch when it happened.

"I heard a big sound. It sounded like something big fell from the next floor. I felt the whole floor shaking," said Jinjoo Yang, explaining her apartment was then filled with smoke.

The NY Daily News noted that firefighters found residents in their fire escapes asking for help.

Victims of the explosion have been brought to the New York Presbyterian/ Weill Medical Center and Bellevue Hospital.

(Video Courtesy of ABC)

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