Rescuers have worked through the night to reach dozens of people believed to be trapped under a collapsed flyover in the Indian city of Kolkata (Calcutta).

The bypass was under construction in the Girish Park area when it collapsed suddenly on Thursday night.

At least 23 people were killed and scores were injured.

The 2km-long (1.2 mile) flyover had been under construction since 2009 and missed several deadlines for completion.

Officials said more than 90 people have been rescued, some of whom where in hospital in a critical condition.

"Many of the people rescued have been seriously injured," police chief Ajay Tyagi told the Reuters news agency.

"Many could still be buried below the debris."

(BBC)