BANGALORE: The death toll from the worst flash floods and heavy rains in decades in southern India rose to at least 172 people Saturday, officials said, as authorities stepped up rescue efforts.

At least 145 people died in the state of Karnataka where army troops and air force helicopters were rescuing marooned villagers and 26 were killed in neighbouring Andhra Pradesh where dams were overflowing, authorities said.

Army boats were also deployed in the rescue efforts.

One more person was killed in the popular southern seaside resort state of Goa in heavy rains that resulted in the collapse of 250 houses, police said.

Officials said the death toll had jumped from 76 to 172 people in 24 hours and warned that number of deaths could rise.

"The toll may go up as we try to reach those areas and villages that remain cut off," H.V. Parashwanath, secretary of Karnataka's disaster monitoring agency, told AFP in Bangalore.

"We are seeing some of the worst flooding since 1972 in the northern part of the state," Parashwanath said, referring to where the Krishna River burst its banks.

Four days of intense rain have submerged villages, destroyed crops and disrupted transport and communication links in parts of the states.

Karnataka's chief minister B.S. Yeddyurappa said the northern part of the state was "reeling" from the heavy rainfall.

Authorities in both states were rushing to shift people living in low-lying areas to school buildings and temples on higher ground.

"We are concentrating on relief operations and evacuation to a safer place," Andhra Pradesh state revenue minister D. Prasad Rao told reporters in state capital Hyderabad.

"The flood is of an unprecedented magnitude," S.A.M. Rizvi, a local administrator in Andhra Pradesh, told the Press Trust of India.