PARIS, June 21 (Reuters) - A blast ripped through a street near Paris' historic Latin Quarter on Wednesday (Jun 21) and rescuers were searching for two missing people feared buried under the rubble of a building that partially collapsed in the explosion.

The explosion tore through Rue Saint-Jacques, which runs from the Notre-Dame de Paris Cathedral to the Sorbonne University, in the late afternoon, injuring at least 37 people, four of whom were fighting for their lives in hospital.

Interior Minister Gerald Darmanin said that sniffer dogs had picked up a scent under the mound of masonry left strewn across Rue Saint-Jacques.

"It is possible tonight that we will find bodies or perhaps survivors," Darmanin told reporters at the scene of the blast.

Witnesses described a deafening explosion and a giant fireball that rose several stories high.

Soldiers helped secure a safety cordon around the scene.

The Paris prosecutor's office said it was too early to say what caused the blast.

But the local deputy mayor, Edouard Civel, referred to a gas explosion in a Twitter post and witnesses told BFM TV there had been a strong smell of gas moments before the blast.

"The shop shook violently, it felt like bomb blast," said Rahman Oliur who manages a food shop a few doors down the street from the American Academy.

Bar worker Khal Ilsey said he heard a "huge explosion" before running out and seeing a violent blaze at the end of the street.