New Delhi (Web Desk): At least 18 people have been killed and dozens trapped in the Indian city of Varanasi after an under construction flyover collapsed, crushing vehicles beneath it, Indian media reported.

According to Officials from the National Disaster Response Force, the flyover was still being built when portions of its cement structure fell on the road being used under it, 18 bodies had been recovered so far and a rescue operation is continuing for those believed to still be trapped, however number of casualties fear t be increased.

Officials reported, rescue operation is underway and at least seven cranes attempted to lift the concrete pillar.

One eyewitness told reporters they were nearby when the collapse happened. "At least four cars, an auto-rickshaw and a minibus were crushed under it," they said, India 's NDTV.

The report said that many of those trapped are believed to be construction workers who had been building the flyover .

An emergency has been declared in hospitals.

The cause of the collapse is not yet known, and an inquiry has been ordered, NDTV added.

National prominent personalities including Moodi, UP CM Yogi Adityanath and Vice president have expresses condolences over the incident.