Mohali (Punjab) [India], December 21 (ANI): A joint rescue operation led by teams of the National Disaster Response Force (NDRF), police and the fire department is underway after a multi-storey building collapsed in Punjab's Mohali on Saturday, a senior police officer said.The police officer also said the number of people "trapped" inside the building is not yet estimated."We received the news about the collapse of a building. It is not yet estimated about the number of people inside (being trapped). Operation is underway," Deepak Pareek, Senior Superintendent of Police (SSP) Mohali told ANI at the spot."All the machines, JCBs, National Disaster Response Force, police and fire department teams are at the spot," the Mohali SSP said.He said that the public is also assisting in the rescue operations."We hope, it will be clear soon if anyone is trapped inside and will be subsequently rescued, " the police officer said.On the reason behind the incident, the official said, "Our Operation is underway. We will come to know about the reason behind the incident". (ANI)