Fourth arrest over deadly India flyover collapse

Three workers were also arrested late Friday, a day after the flyover crashed down onto the busy street in the eastern city, crushing pedestrians and vehicles.

All four are from IVRCL, the contractor behind the ill-fated construction project in West Bengal state, and face initial charges of murder, conspiracy and mischief, joint police commissioner of Kolkata Debasish Boral said.

"The assistant general manager was initially detained while he was trying to flee on Friday night," Boral said.

"He was arrested on Sunday after questioning," he told AFP.

Although officials have ruled out the chances of finding any more survivors under the rubble, rescuers continued on Sunday to search for victims, using cameras inserted in spaces under the blocks of concrete and twisted girders.

"Such cameras were widely used during the Nepal earthquake rescue operation last year," engineer Sumit Lahiri, who is working at the site, said.

He also said workers were trying to stabilise parts of the wrecked flyover that were still dangling dangerously overhead.

Rescuers pulled nearly 100 people out alive from under the huge concrete slabs and metal girders that fell onto the street immediately after the disaster.

IVRCL has denied responsibility for the accident, but a company representative infuriated victims on Thursday when he described the incident as an "act of God".

The tragedy is the latest in a string of deadly construction accidents in India, where enforcement of safety rules is weak and substandard materials are often used.

It comes at a sensitive time for Chief Minister Mamata Banerjee, as West Bengal heads to the polls on Monday in state elections to be held in phases in coming weeks.