Towns and villages have been flooded and thousands of homes destroyed after a super-cyclone crashed ashore in eastern India. But initial indications suggested few people had died after more than 500,000 had left the region before the storm hit.

The vast weather system – cyclone Phailin – generated winds of up to 135mph (220km/h) and forced huge waves far inland before it struck the shores of Odisha and Andhra Pradesh states late on Saturday.

But the storm weakened as it made landfall. Officials said they knew of only seven fatalities – most of whom were killed by falling branches or collapsing buildingsahead of the cyclone.

The final death toll is expected to climb, and parts of the cyclone-battered coast remain isolated by broken communication links and blocked roads. But initial indications were that the government's evacuation operation saved many lives.

"Damage to property is extensive," said Amitabh Thakur, the senior police officer in the Orissa district worst-hit by the cyclone. "But few lives have been lost," he said, crediting the mass evacuations.

Among the first reported deaths, two people were killed by falling trees while a third died when the walls of her mud house collapsed. Another two people died as the storm pressed inland, authorities said.

Reporters described terrified children clinging to their mothers as they sought shelter. Most towns along the coast were deserted but there were still some residents trying to flee.

Authorities combed coastal areas for fishing communities unwilling to abandon their boats or others still in the danger zone. Police forcibly evacuated thousands, officials said. Some people took refuge in temples, while others crammed into auto-rickshaws and headed inland.

Large numbers of troops were deployed and huge amounts of emergency food stockpiled, Indian media reported.

"This is one of the largest evacuations undertaken in India," said Shashidhar Reddy, vice-chairman of the National Disaster Management Authority, who estimated that more than 440,000 people had fled from their homes. Other estimates were as high as 550,000.

The storm destroyed tens of thousands of mud huts and sent seawater surging inland.

"Its intensity is still strong, but after crossing the coast it has weakened considerably," Sharat Sahu, an official with the Indian Meteorological Department in Orissa told reporters.

The storm was expected to cross half of India before losing strength over the central highlands of the vast country by the middle of next week.