17 killed as under-construction bridge collapses in Kolkata, India (VIDEOS, PHOTOS)
The incident took place near Girish Park in North Kolkata.
Eyewitnesses told the Indian Express they heard a loud blast and a crashing sound. They also said they saw a cloud of smoke rising from the scene.
Numerous photos on social media show people gathered near the scene of the incident trying to help those trapped or injured.
WATCH: Rescue ops underway for those trapped under debris after under-construction bridge collapses in North Kolkatahttps://t.co/t96fZB3Qpr— ANI (@ANI_news) March 31, 2016
"The condition is pathetic. At this moment no one has any clue how many people are trapped," said Raichand Mohta, a police officer at the scene, told Reuters.
The Indian Express cited locals who said they opposed the construction, saying the overpass crosses too close to multi-story buildings nearby.
Paramedics are working to free people from a minibus that was crushed in the collapse, a local witness told Reuters.
The flyover collapsed on to the traffic moving along the street, police said.
"Cement and concrete were poured in yesterday only, it suddenly collapsed today," a local witness told India Today.
Those who happened to be near the scene were trying to pass bottles of water to people trapped in the rubble.
NDTV reported of a huge blaze at the scene, citing fire officials.
The Indian Army is heading to the disaster zone to assist.
Kolkata police have reportedly filed a notice against the IVRCL transportation company over the incident, Indian media said.