(Adds typhoon makes landfall, 1 million people evacuated)
By Rosemarie Francisco
MANILA, Dec 6 (Reuters) - A powerful typhoon roared into the eastern Philippines on Saturday, bringing lashing rain and strong winds that felled trees, ripped off tin roofs and toppled power lines in areas still bearing the scars of a super typhoon 13 months ago.
About 1 million people had already fled to shelters by the time Typhoon Hagupit made landfall, in what a U.N. agency said was one of the world's biggest peacetime evacuations.
As the storm barrelled in from the Pacific, power was cut across most of the central island of Samar and nearby Leyte province, including Tacloban City, considered ground zero of the devastating super typhoon Haiyan last year.
"The wind is blowing so strongly, it's like it is whirling," Mabel Evardone, an official of the coastal town of Sulat in Eastern Samar, said on local radio. "The waters have risen now."
There was no word of any casualties.
Hagupit had weakened to a category 3 storm, two notches below "super typhoon," but could still unleash huge destruction with torrential rain and potentially disastrous storm surges of up to 4.5 meters (15 ft), the weather bureau PAGASA said.
The eye of the typhoon hit the town of Dolores, Eastern Samar at 9:15 p.m. (1315 GMT), PAGASA said, adding the storm maintained its strength, with winds of up to 175 kph (110 mph) near the center and gusts of up to 210 kph (130 mph).
"We can expect that heavy rains were dumped on Eastern Samar because Ruby hovered for a long time over the coastal areas," weather forecaster Jori Loiz said on radio, referring to the local name of typhoon Hagupit.
The weather bureau said Hagupit - which means "lash" in Filipino - maintained its projected path towards Masbate, Romblon and Oriental Mindoro provinces, slightly north of areas devastated by super typhoon Haiyan last year.
PAGASA earlier said the storm was moving north northwest at 16 kph (10 mph).
"Ruby's lashing will be severe," Interior Secretary Manuel Roxas told government radio. "Let's be alert. Let's evacuate to prevent any harm to your families."
Philippine Airlines and Cebu Pacific canceled about 100 flights to central and southern Philippines on Saturday.
Residents of low-lying villages and landslide-prone areas have fled to schools, civic centers, town halls, gyms and churches, the national disaster agency said.
"We received reports about a million people evacuating already. There is increased awareness to make early action and co-operate and do pre-emptive evacuation," Gwendolyn Pang, secretary general of the Philippine Red Cross, said in a television interview.
At least 50 municipalities in the central Philippines and the southern part of the country's main Luzon island were at risk of storm surges, the Science and Technology department said.
The typhoon was unlikely to hit the capital Manila, home to around 12 million people, the agency said.
"Typhoon Hagupit is triggering one of the largest evacuations we have ever seen in peacetime," said Denis McClean, spokesman of the United Nations Office for Disaster Risk Reduction in Geneva.
Relief agency Refugees International said in a statement it was "deeply concerned" that evacuation centers may not be safe.
"A damage assessment of designated evacuation centers in typhoon-affected areas indicated that in some places - such as Eastern Samar, where Hagupit is headed - less than 10 percent of evacuation centers were likely to withstand future typhoons," the group said.
The United States had offered to send nine C-130 transport aircraft, three P-3C Orion, and medical and relief workers, said Major Emmanuel Garcia, commander of the Armed Forces' 7th civil relations group.
Other foreign governments also sent word they were ready to help the disaster-prone Southeast Asian nation, he said.
The islands of Samar and Leyte were worst-hit by 250 kph (155 mph) winds and storm surges brought by Typhoon Haiyan in November.
"There has been a tremendous amount of learning from last year," said Greg Matthews, emergency response advisor at the International Rescue Committee. "There have been reports from our field officers and partners that people are evacuating themselves. They are aware of the situation."
Haiyan, one of the strongest typhoons ever to make landfall, left more than 7,000 dead or missing and more than 4 million homeless or with damaged houses. About 25,000 people in Eastern Samar and Leyte still live in tents, shelters and bunkhouses.
International humanitarian agencies and non-government groups, which have been supporting Haiyan-devastated communities in the central Philippines, are preparing to mobilize aid and relief efforts in the aftermath of Typhoon Hagupit.
Soldiers were deployed to urban centers, particularly in Tacloban City, where widespread looting broke out after Haiyan.
"The soldiers will help our police counterparts in maintaining peace and order, and prevent looting incidents," said Colonel Restituto Padilla Jr, armed forces spokesman.
(Additional reporting by Jazmin Bonifacio in Samar, Neil Jerome Morales and Erik dela Cruz in Manila and Stephanie Nebehay in Geneva; Editing by Alex Richardson)