At least 27 people were killed and 12 severely injured in a fire at a four-storey building in Delhi’s Mundka locality on Friday, police said.

Sources said the police and fire-fighters rescued many people while others jumped to safety or were helped by neighbours with ladders and ropes.

Harish and Varun Goel, owners of an electronics unit where they blaze occurred have been arrested by the police. There seems not to have been a fire exit.

They have been arrested after an FIR was lodged against them under IPC sections 304 (culpable homicide not amounting to murder), 308 (attempt to commit culpable homicide), 120 (concealing design to commit offence punishable with imprisonment), 34 (acts done by several persons in furtherance of common intention).

Delhi minister Satyendar Jain inspected the building after the smoke subsided around 11.15pm, confirmed the death toll, and promised action.

“I salute the courage of the firemen who jumped into the fire to save people. Our priority is to search for survivors right now…. This building did not have a fire (department) no-objection certificate,” he said.

DCP (Outer) Sameer Sharma said the fire was reported at 4.45pm. “Police officials broke the windows to rescue inmates and got the injured to hospital,” he said.

Deputy chief fire officer Sunil Choudhary told reporters that many people jumped out of the building.

Some 150 people including a large number of women worked there. Some of them broke windows. Local people too helped by breaking windows, throwing ropes and putting up ladders before the fire brigade cranes arrived.

Some of the ropes broke under the weight of people, eyewitnesses said. Fire engines were reportedly stuck in a traffic jam on Rohtak Road for a while on their way to the building, located near Mundka metro station.

“The main entrance was shut when the fire service arrived,” minister Jain said.

“The fire started from the first-floor… office of a CCTV camera and router manufacturing and assembling company,” Sharma said.

“Over 50 employees of the company are reportedly rescued…. More than 30 fire tenders were pressed into service.”

Neither police nor fire service officials have revealed the cause of the fire so far. The investigation, they said, will begin when the search ends and the smoke dies down.

Fire-fighters and police had begun searching the building after 9pm when most of the fire had been put out, although small fires burnt on the upper floor off and on.

Union home minister Amit Shah tweeted that the National Disaster Response Force was being sent to help the search.

Prime Minister Narendra Modi announced Rs 2 lakh each for the families of the dead and Rs 50,000 for the injured.

Delhi witnesses fires every summer because of poor observance of safety norms. A smaller fire was reported from a shopping complex on Friday but no injuries seemed to have occurred.

The Mundka fire is Delhi’s worst since 2019, when 43 people died in a blaze at an unauthorised paper factory in Anaj Mandi. Delhi’s worst fire tragedy remains the one that killed 59 people in Uphaar cinema in 1997.