The incident took place when the roofs along the T-iron collapsed.
Two labourers were rescued from the debris, four hours after two floors of an under-construction building collapsed in south Delhi's Ambedkar Nagar area on Thursday, police said.
The police received information about two floors of a building collapsing at J-Block, DDA Market, Dakshinpuri around 4.25 pm, a senior police officer said.
After receiving information, five water tenders were sent to the spot, Delhi Fire Services Director Atul Garg said.
The two labourers who were rescued in the joint rescue operation by police and Delhi Fire Services sustained minor injuries and were sent to hospital for treatment, the police said.
According to officials of the Municipal Corporation of Delhi, the construction work in the building was halted for a while and had resumed recently on the third and fourth floors.
The incident took place when the roofs along the T-iron collapsed, leaving the labourers trapped, the officials said.
Action has been initiated against those responsible under the Delhi Municipal Corporation Act, they added.
It is suspected that heavy rainfall in the city was a possible cause behind the building's collapse, the police said, adding that a case is being registered in connection with the incident.
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