Police say many people are feared to be trapped after a portion of an overpass under construction collapsed in a congested area in eastern India.

The New Delhi Television news channel says at least one person was killed in the collapse on Thursday in the eastern city of Kolkata.

Police officer Subhankar Sinha says efforts are underway to rescue those trapped under the debris.

Building collapses are common in India, where builders use poor enforcement of regulations and use substandard materials.