MANILA (Reuters) - The Philippines declared a state of calamity in a northern province after super typhoon Megi hit on Monday, cutting off power and communications, forcing flight cancellations and putting the region's rice crop at risk.
Megi, the 10th and strongest typhoon to hit the Philippines this year, hit Isabela province at 11:25 a.m. (0325 GMT) and by early evening was heading west-southwest across the north of the main island of Luzon with winds of 110 mph near the center, forecasters said.
Tropical Storm Risk (www.tropicalstormrisk.com) said Megi, known locally as Juan, was a category 5 super typhoon, the highest rating, with winds of more than 250 kph (155 mph) when it hit mountains in northeast Luzon at 11:25 a.m. (0325 GMT)
"The governor of Isabela declared a state of calamity, so there could be massive damage and destruction there," Benito Ramos, executive director of the national disaster agency, told reporters.
"Power has been cut and crops about to be harvested could have been destroyed. We have no actual report because we're waiting for the weather to clear up to make an assessment."
Initial reports were of one death and a small number of casualties, although the National Telecommunications Commission said up to 90 percent of communications in Isabela and Cagayan provinces may have been knocked out.
Television footage showed uprooted trees on roads, and metal and thatched roofing blown off houses.
In six hours from 8 a.m. (0000 GMT), the city of Tuguegarao in Cagayan had 2.2 inches of rain, while Baguio City on the western side of Luzon had 28 mm, the weather bureau said.
The typhoon is expected to clear Luzon island around midnight on Monday, and head across the South China Sea toward China.
Angelito Banayo, administrator of the National Food Authority (NFA) told Reuters the government's worst case scenario was Megi could damage 232,169 tonnes of unmilled rice crop in the north with only 30 percent of it able to be harvested.
The Philippines is the world's biggest rice importer and damage from the typhoon could see it buy more than had been expected for 2011, which could push up international prices.
Andrew Villacorta, regional executive director in the agriculture department, said the Cagayan valley accounted for 12 percent of national rice output, or about 1 million tonnes of unmilled rice.
He said just over one third of the crop had been harvested, while about 90 percent of the corn crop had been harvested.
Last year, the country lost 1.3 million tonnes of paddy rice following three strong typhoons in September and October, prompting it to go to the market early to boost its stocks.
"This could bring destruction to our crops," Val Perdido, a regional farm official, told reporters.
"It's the peak of harvest season now. More than 230,000 hectares of rice fields are still in their reproductive and maturing stages."
Agricultural production makes up a fifth of the Southeast Asian country's GDP.
Local officials in Isabela province declared a state of calamity to ensure food and energy supply and spend more on rescue, relief and rehabilitation work after the typhoon leaves, officials at the disaster agency said.
There were warnings flash floods, river banks breaking, and landslides in mountain areas of Luzon, and heavy rains were still expected in the typhoon's tail.
Officials said the U.S. military, holding a nine-day drill with Filipino counterparts, had offered seven helicopters to deliver relief goods and rescue marooned residents if needed.
After clearing the Philippines, Megi will head out into the South China Sea. Tropical Storm Risk's projections show the storm is expected to turn away from Vietnam toward China, with the center passing between Hainan island and Hong Kong.
China's National Meteorological Center said Megi may be the worst to hit the country this year.
Some 140,000 people were evacuated from 15 cities on Hainan island since heavy rains reached the province on Friday, the official Xinhua News Agency reported on Monday.
Disaster-response authorities ordered officials along the Chinese mainland coast to ready emergency supplies and prepare residents for possible floods and landslides with torrential downpours likely in coming days, including in provinces inland, Xinhua reported.
The storm seemed set to miss Vietnam, where severe flooding in central regions has killed 31 people, left several missing and inundated scores of communities in recent days, state television reported on Monday.
($1 = 43.2 pesos)
Additional reporting by Eric dela Cruz in Manila, John Ruwitch in Hanoi and Chris Buckley in Beijing; Editing by John Mair and Alex Richardson