At least nine people from two families, including a toddler, were killed after a fire swept through a four-storey residential building in east Delhi’s Vivek Vihar early on Sunday, with the preliminary probe suggesting an AC blast as the possible trigger.

Delhi fire services officials said they received a call about the blaze at 3.47am and rushed multiple teams to the spot. By 5am, 14 fire tenders had joined the rescue efforts.

A police officer said the fire first caught onto household items and swiftly spread to at least six flats.

“Prima facie, the fire is believed to have been caused by an AC blast. The flames engulfed flats on the second, third and fourth floors and were brought under control after four hours. Nine bodies were recovered from different parts of the building,” he said.

According to him, five bodies were recovered from the second floor of the building, while three more were found near the staircase on the third floor. Another body was found on the first floor.

“We rescued 15 people during the firefighting operation. Two of them were injured and were rushed to a hospital,” the official said.

The building, he said, housed four flats on each floor and protective iron grilles and barred windows hampered rescue efforts.

Forty-five-year-old Shikha Jain, who lived on the first floor, was among the deceased. The victims on the second floor — a family of five — were identified as Arvind, 60, Anita Jain, 58, Nishant Jain, 35, Anchal Jain, 33, and one-and-a-half-year-old Akash. The deceased on the third floor also belonged to a single family — Nitin Jain (in his 50s), his wife Shailey Jain, 48, and their son Samyak Jain, 25.

Mayank, a first-floor resident, said he was sleeping when neighbours rang his doorbell multiple times.

“When I woke up, I saw the rear portion of the building in flames. I somehow managed to escape from my flat. The staircase was blocked by the fire. Residents from flats at the back of the building got trapped as there was no escape route,” he told reporters.

Ruchi Arora, 60, another first-floor resident, said they were “stuck inside for an hour and a half” before being rescued by the fire department.

Delhi BJP president Virendra Sachdeva said: “The scene inside the building was heart-wrenching. Nine people have died. The fire started from sparks in the AC unit. The police and local people saved the lives of 20 people.”

BJP MLA Sanjay Goel told reporters: “A short circuit is said to have caused this incident. However, some are saying it happened because of a blast in the AC.”

Delhi chief minister Rekha Gupta said the incident was “extremely tragic”, adding that the loss of nine lives in the blaze had left her “deeply depressed”.

“Treatment of the injured in the accident is ongoing at the nearest hospital, and I pray for their swift recovery. In this hour of grief, my condolences are with the affected families. I pray to God to grant them the strength to endure this difficult time,” she posted on X.