Aug. 3: A long stretch of a British-era bridge on the busy Mumbai-Goa highway was swept away last night, triggering an intense search to establish whether a bus carrying 22 people and eight other vehicles had fallen into the river.

Maharashtra police said there was no trace of the buses or other vehicles till this evening.

Constructed by the British in 1928, the bridge ran across the Savitri river at Mahad in Raigad, some 170km south of Mumbai. Even after a parallel bridge was built in 2001, the old one continued to be in use because of the heavy traffic on the highway.

"The arches on which the bridge rests are all interconnected. If one arch falls, the entire bridge collapses like a pack of cards," an official said. "Three years ago, the bridge had been reinforced with crash bearings but the agency that built the bridge had communicated to the government in the late 1990s that the bridge was past its life," he added.

The Indian Navy and the Coast Guard have deployed search teams, along with over a hundred rescuers of the National Disaster Response Force and local police, across an 18km stretch from the bridge to Harihareshwar where the river meets the Arabian Sea. Helicopters and at least one all-weather aircraft have also joined the search.

Witnesses have told the administration that two buses might have been swept away. Two buses scheduled to reach Mumbai this morning did not do so. Neither the drivers and conductors nor the passengers could be reached on their phones, local television reports quoted relatives and transport officials as saying.

Witnesses said eight private vehicles, including a couple of cars, also fell into the river.

Vasant Kumar, a mechanic who lives near the site, told a Marathi TV channel that the old bridge collapsed around 11.30pm. The bus drivers may not have realised that three-fourths of the bridge had collapsed, he added.

The Maharashtra government has announced a structural and safety audit of 36 British-era bridges on the Mumbai-Goa highway.