At least four more bodies were recovered from the district of Raigad, where the British-era bridge on the Mumbai-Goa highway had collapsed on Wednesday, taking the death toll to six. The Maharashtra Government has ordered a judicial probe into the incident.

A boat belonging to the National Disaster Response Force (NDRF) also capsized during the search operation. However, all officers were rescued and are safe.

A body of a woman was retrieved near Harihareshwar in Raigad, while another body of a driver of one of the missing buses was found in Dapoli's Anjarle area.

Both the buses – one travelling from Jaigad to Mumbai and the other from Rajapur to Borivali - had reached Poladpur bus terminus at 11:10 p.m. on Tuesday. However, when they did not reach the Mahad Bus Stand 20 minutes after the scheduled time, an alarm was raised, the Indian Express reported.

At least 30 people are still missing and search operations are still underway to locate them. The missing vehicles, washed away due to the collapse, include a private Chevrolet Tavera car that was carrying around nine people, besides the two Maharashtra State Transport buses that were carrying 22 people.

The NDRF rescue teams lowered a 300 kg magnet into the swollen Savitri river on Thursday morning in an attempt to locate the two missing buses and other vehicles.

"We suspect that one of the buses may be at the centre of the river but the current is very strong there. We are not able to deploy our boats or divers; the water keeps throwing everything out. So we have used a local method and sunk heavy iron hooks and magnets into the river, which locals say is 40 feet deep," Anupam Shrivastav, Commandant, 5th Battalion NDRF, told IE.

A local official said that something got stuck onto the magnet and efforts are on to pull it out of the river, according to local media reports.

Around 28 Marine Commandos, the Indian Coast Guard's Chetak helicopters along with 25 personnel, Indian Air Force's Mi-17 helicopter and the Navy's Sea King 42C and 42B helicopters have been deployed to assist in the search and rescue operation. The diving teams of the Indian Navy have also joined the NDRF as ground support.