At least 12 persons were rescued in the early hours of Wednesday after a four-storey residential building collapsed in Uttar Pradesh’s capital Lucknow, reported The Indian Express.

Teams of National Disaster Response Force, State Disaster Response Force, local police and fire brigade are still carrying out the rescue operation at the site.

“The estimate is that maximum 12 more people are trapped inside,” Uttar Pradesh Director General of Police DS Chauhan told mediapersons, reported The Indian Express.

On Tuesday, three persons had died after the building collapsed in the city’s Hazratganj area. The incident happened after an earthquake of 5.5 magnitude was felt in Lucknow. The building, named Aliyah Apartment, had 12 flats and two penthouses on the top floor. It was also situated at a riverine belt.

The builder was allegedly constructing a basement by breaking some columns of the building, reported the Hindustan Times. Lucknow Divisional Commissioner Roshan Jacob has claimed that the building was illegal since its map was not approved by the authorities, reported the newspaper.

No arrest has been made in the case so far. However, Chauhan has said that the police will take strict action against persons responsible.

Meanwhile, Union Defence Minister and Lok Sabha MP from Lucknow Rajnath Singh on Tuesday expressed his condolences to the families of the deceased.