Rescuers are digging through large chunks of debris from a flyover which collapsed while under construction in the Indian city of Kolkata.

At least 18 people have been killed and more than 70 injured in the accident took place in a densely populated area, with narrow lanes, and shops and houses built close together.

A section of the overpass in a busy residential and shopping area fell on traffic and people moving underneath.

Ramesh Kejriwal saw it happen: