A massive fire broke out in three buildings in Delhi's Azad market area on Saturday morning and one of them, a four-storey structure, collapsed, officials said.

Five people suffered minor injuries after a cylinder exploded at a shop. It is suspected that the cause of the fire was a short circuit in an electric pole, police said.

Twenty fire tenders were rushed to the spot after information about the blaze was received, the fire department officials said. The fire was brought under control at around 7:30 am and doused by 8:30 am, they said.

Delhi Chief Minister Arvind Kejriwal wished for the "speedy recovery" of the injured.

"I received the sad news of the fire incident in the morning. I thank god that there was no loss of life. The fire brigade and disaster management teams have bravely handled the situation. I wish a speedy recovery to all those injured in this accident," Kejriwal said in a tweet in Hindi.

A senior police officer said after receiving information about the incident at the market's main road area, fire tenders were called in. The building, where the fire broke out, collapsed and it housed some small shops which sold goods like paint, tarpaulin sheets and bags, the officer said.

The cylinder explosion took place in a welding shop, Deputy Commissioner of Police (North) Sagar Singh Kalsi said.

Five people suffered minor injuries due to splinters from the explosion and they are now safe, he said, adding that a case under sections 285 (negligent conduct with respect to fire or combustible matter), 336 (act endangering life or personal safety of others) and 337 (causing hurt by act endangering life) of the Indian Penal Code has been registered at the Bara Hindu Rao Police Station.

Disaster management teams were deployed and earthmoving machines were called to remove the debris from the collapsed building, the DCP said. A car parked nearby also caught fire, police said.

Investigation is underway to ascertain the exact cause of the fire, police said.