Chennai: Over 150 cars were gutted on Sunday when a major fire swept through a parking lot at a suburban neighbourhood, with thick columns of black smoke engulfing the entire area, inconveniencing the people and causing anxiety.

Some vehicles that had gas in fuel tanks exploded, but no one was injued, a fire service official said.

"The blaze is suspected to have been triggered after tall dried grass caught fire by a discarded smouldering cigarette butt," a suburban Fire and Rescue Services official told PTI.

Of the total 208 parked cars, 176 were gutted and 32 were "saved from the fire," he said.

The cars were parked "bumper to bumper" in close proximity and is suspected to have been one of the reasons for the blaze having spread so quickly.

The parking lot is situated bang opposite a large private sector medical college and hospital at suburban Porur.

Several road users and local residents said huge colums of smoke billowed out of the facility, causing anxiety and inconvenice.

The impact of the fire could have been much more if the parked vehicles had petrol in fuel tanks, the fire official said.

Seven fire tenders and four water tankers were deployed to fight the blaze and it took abour four hours to douse the flames, he said.

Initial enquiries revealed that fire had broken out on at least three occasions in the past in the same premises, he said.

The watchman of the facility fled from the premises following the blaze and alerted the authorities.

"Since tyres and plastics went up in flames it led to thick fumes of smoke."

Asked if the cars were new or if it was only a parking lot run by some commercial firms, the official said "an enquiry is on by police....

...it seems to be a mix of cars; some cars are reportedly used ones seized for non-payment of EMI and others are said to be new, some unsold vehicles..authorities are questioning some persons and a full picture will emerge later."

The incident was similar to the one at the Aero-India show at the Yelahanka Air Force Station at Bengaluru Saturday, where about 300 cars in the parking area were gutted.

No casualties were reported in that blaze, which too was suspected to have been caused by dry grass fire aided by heavy winds.