At least 77 bodies have been recovered after two-packed passenger buses were swept away in floods in India's Tamil Nadu state, officials say.

Search operations are continuing and it is feared that the death toll could rise further.

In one incident, in Thanjavur district, 50 bodies have been found. In the other in Ramnad district, 27 were killed.

Heavy rain has been falling in the area for the past week, flooding villages and thousands of hectares of land.

The disaster in Thanjavur district happened near Pattukkottai. The driver is believed to have lost control of his heavily crowded vehicle as it was crossing a flooded river.

The district administration has mounted a massive search and rescue operation.

Arrests

Earlier in the day, a bus travelling from the city of Tiruchchirappalli to Rameswaram on the coast was swept away by flash floods.

The bus was swept from a bridge into the Sarugani river. Naval helicopters were scrambled to help the rescue operation.

Rescuers said the bus plunged from a causeway at a point where the Sarugani river merges with the Indian Ocean.

Police told Associated Press the driver and conductor were arrested for defying a police order not to cross the bridge.

The BBC's TN Gopalan in Madras says Tamil Nadu has received exceptionally heavy rains in the north-east monsoon that broke in the third week of October.

Before Friday, around 100 lives had been lost and hundreds of huts washed away.

The most recent heavy spell of rain started a few days ago and has been particularly intense in southern regions.

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