The incident occurred in Ullawas village. The Fire Department received a call at 5.15 a.m.

"State Disaster Response Force (SDRF) and Border Security Force (BSF), from its nearby base camp has reached the spot. Fire Department, police and distric administration with JCBs have started the rescue.

"The National Disaster Response Force's (NDRF) help has also been sought," the official added.

"The rescue teams are facing problems in removing concerte material, iron grills and debris. There are seven people feared trapped. All are labourers," Chief Fire Officer Isham Singh said.

"The building was a three storey structure earlier. One more concrete roof was placed on Wednesday for the fourth floor, which appeared to have first shattered resulting in the collapse of the entire building immediately," Singh said.

"No one has been rescued as the rescue teams were still searching for those trapped. They are still removing the heavy concretes material and iron grills. Efforts are on," Gurugram police PRO Subhash Bokan said.

"The building belongs to a resident of Ullawas Village. It was setup on 125 square yard land. Police teams are looking for him," Bokan added.

Unconfirmed eyewitness accounts to the police had earlier put the number feared trapped at 20.