IN DISTRESS People wait to be rescued in a country boat in a flooded area at Kainakary in Alappuzha district in India. AP NEW DELHI — Rescuers used helicopters and boats on Friday to evacuate thousands of people stranded on their rooftops following unprecedented flooding in the southern Indian state of Kerala that killed more than 320 people, officials said.

“Kerala state is facing its worst flood in 100 years,” the top state elected official, Pinarayi Vijayan’s office tweeted.

With heavy rains stopping after a week, rescuers moved quickly to take those marooned by floods to 1,500 state-run camps. They used more than a dozen helicopters and about 400 boats across the state, relief officials said.

Vijayan told reporters that at least 324 people had died and more than 220,000 had taken refuge in the camps.

Heavy rains over the past eight days triggered flooding, landslides and home and bridge collapses, severely disrupting air and train services in Kerala state, a popular tourist destination with scenic landscapes, waterfalls and beautiful beaches.

The New Delhi Television news channel reported that the state was facing a new crisis with some hospitals facing shortages of oxygen and gas stations running short of fuel.

According to India’s weather bureau, since the beginning of June more than 321 centimeters of rain has fallen on the hilly central district of Idukki, which is now virtually cut off from the rest of the state.

The Kerala government has said it faces an “extremely grave” crisis and Vijayan warned of further torrential rainfall hitting the region over the weekend.

The gates of dozens of dams and reservoirs across the state have been opened as water levels reach danger levels, inundating many other villages.

The monsoon flooding has severely hit 12 of Kerala’s 14 districts, with thousands of homes damaged since June. Crops on 32,500 hectares of land have also been damaged, the Home Ministry said.

The international airport at Kochi, a major port city, suspended flight operations until Saturday after the runway was flooded. Authorities also asked tourists to stay away from the popular hill station of Munnar in Idukki district because of flooding.