Two people were killed and two others injured Saturday night in an explosion and massive fire in Indianapolis, authorities said.

Two houses were completely blown up, while several houses in the vicinity were razed by the engulfing flames, displacing hundreds, a fire department spokeswoman said.

The cause for the explosion, which occurred around 11 p.m. Saturday is not yet known. Investigators are looking at natural gas as a possibility, as there were reports of strong odor of natural gas near the area.

The details of victims are yet to released by the authorities.

Two houses exploded sparking fires in the adjacent houses, Lt. Bonnie Hensley, a spokeswoman for the Indianapolis Fire Department told the Chicago Tribune.

"It looks like a war zone here right now," Hensley said.

Indianapolis Mayor Greg Ballard, who visited the area, dismissed the possibility of a plane crash triggering the explosion.

"It was so strong that it clearly had an effect for blocks. We're going to need some comforting in the next few days," the mayor said.

The fire damaged a dozen homes and about 2,000 people have been evacuated to a nearby school, while many others took refuge with family or friends. People were caught unawares sleeping and most of them fled their houses in pajamas and with their pets.

The fire was brought under control by early Sunday morning. Police have cordoned off the area.