New Delhi |The death toll in the building collapse in southwest Delhi's Satya Niketan area rose to seven on Monday as search and rescue operations entered the second day.

So far, 12 people have been rescued from the debris of the decades-old multi-storey building.

National Disaster Response Force Inspector General (IG) Narendra Bundela said on Monday that the federal contingency force did not have a "specific figure" on the number of people trapped under the debris.

According to Bundela, the rescue operation being undertaken by the NDRF and sister agencies from the Delhi government is expected to last till late Monday.

Earlier in the day, All India Institute of Medical Sciences (AIIMS) said 11 patients were received at the JPN Apex Trauma Centre following the building collapse.

"Out of the 11 patients, five were brought dead, while one patient who was in critical condition later succumbed to his injuries; three patients have been admitted and are being treated. One patient underwent limb surgery. One patient had sustained a minor injury and was discharged after observation," the statement read.

The building, which housed a boys' paying guest accommodation near Delhi University's South Campus, collapsed around 1.30 pm on Sunday while repair work was underway.

Multiple agencies, including the Delhi Police, Delhi Fire Service, National Disaster Response Force and Delhi Disaster Management Authority, have been carrying out rescue operations through the night.

Police have registered a case against the building owner and others, while a magisterial inquiry has also been ordered.