Delhi Fire Services (DFS) chief Atul Garg said that a call regarding the fire at a factory in Bawana Industrial area was received at around 3.05 p.m.

Nine persons were rescued and rushed to a nearby hospital, the police said, adding that of the six injured, three are in critical condition.

"A total of 20 fire tenders were pressed into service to bring the blaze under control," Garg, meanwhile, said.

A police officer said that three individuals who are in a serious condition were identified as Kuldeep (18), Bablu (25) and Mastram (20), and all of them have been referred to Safdarjung Hospital for further treatment.

The other injured - Suresh, Rakesh, Pankaj Pal and Ghan Shyam are undergoing treatment at a hospital.

"As per factory owner Sunil Kumar, a resident of Rohini, no one is trapped inside so far, but it will be confirmed after complete operation and the cooling process is going on," said a senior police officer.

An initial probe suggested a short circuit caused fire in chemicals that are highly inflammable.

The police officer said that legal action is being taken against the owner of the factory.