At least 11 workers have been killed and many are feared trapped after a half-built apartment block collapsed in the Indian resort state of Goa.

The three-storey building in Canacona, just over 4km from the popular Palolem beach in India's smallest state, collapsed yesterday.

Senior police official OP Mishra said 11 workers were killed and 21 had been rescued so far.

Other media reports put the death toll at 14 and the number of those trapped as high as 60.

Dozens of people were working on the site at the time of the accident, according to witness accounts.

India's booming construction industry is set to be worth €1 trillion by 2025, which would make it the world's third largest, according to a report by Global Construction Perspectives and Oxford Economics.

But concerns have been rising over lax safety standards.

At least 50 people were killed when a five-storey apartment block in India's financial centre, Mumbai, collapsed last September.

A collapse in April killed 72 people in Thane, a satellite city just outside Mumbai.

Goa police have registered a case against the real estate development firm building the Goa block.

"Legal action will be taken against all who are responsible for this," Mr Mishra said.