Eleven people were killed and as many injured after a multi-storey residential building collapsed in northeast Delhi’s Mustafabad on Saturday.

Teams from the Delhi Disaster Management Authority, the National Disaster Response Force, the Delhi Fire Service and police were rushed to the spot and carried out rescue work for over 12 hours.

Police said there were 22 people in the 20-year-old four-storey structure in Shakti Vihar that caved in around 3am. The owner of the building, Tehseen, and six from his family were among the deceased.

The injured were rushed to GTB Hospital. Six people were discharged after receiving treatment, which included the owner’s son Chand. Nine people, including Tehseen’s wife, are still under treatment.

People living in the vicinity of the building said they felt the tremors and thought an earthquake had struck. “We thought something hit our house but when we looked outside, we saw that the entire building next to us had turned into rubble,” Ryan, a Shiv Vihar resident who lived next to the collapsed building, told PTI.

Ajith R., deputy commandant of 16-NDRF, said his team reached the location at 4.50am after receiving a call from the Delhi police control room. “Initially, the police reported that around 15 to 20 people were trapped under the rubble. Around 10-14 of them were rescued by locals and other agencies before our arrival. The NDRF team rescued eight people,” he said.

Delhi chief minister Rekha Gupta has ordered a probe and promised strict action against the guilty.

“Deeply saddened by the tragic building collapse in Mustafabad. Orders have been given to investigate the incident and strict action will be taken against the culprits,” she posted on X.

“My deepest condolences to those who died in the unfortunate accident. May God grant peace to the departed souls and give strength to the bereaved families to bear this irreparable loss,” she added.

Gupta told reporters that contractors and builders who flout rules to construct such fragile buildings and the officers who allow this shouldbe punished.

Former Delhi chief ministers Arvind Kejriwal and Atishi appealed to AAP workers to cooperate with the administration in relief and rescue operations.

Delhi law minister Kapil Mishra blamed Kejriwal for turning a blind eye to“illegal” constructions during the AAP government’s tenure and claimed that innocent people were paying the price of such practices.

In a post on X, Mishra said: “The collapse of the illegal building in Mustafabad exposes the real truth of Kejriwal gang’s corruption in the Municipal Corporation.”

He demanded a survey on illegal buildings and strict action against the builders.