Residents of flooded farming villages in the Philippines were trapped on their rooftops on Monday and animals floated down fast-rising rivers, as deadly Typhoon Koppu dumped more intense rain.

Koppu, the second strongest storm to hit the disaster-plagued Southeast Asian archipelago this year, has killed two people and forced more than 60,000 people from their homes, authorities said.

After making landfall on Sunday morning on the east coast of Luzon, the Philippines' biggest island, the slow-moving typhoon has brought heavy rain to some of the nation's most important farming areas.

"I've never seen anything like this. It's the worst flood I've seen in my entire life," farmer Reynaldo Ramos, 68, told AFP as he walked through knee-deep water in Santa Rosa, about two hours' drive north of Manila.

Military, local government and volunteer rescue units were trying to help residents in about 70 villages that were under water, with the floods spreading, according to Nigel Lontoc, a regional rescue official.

"The floods are rising fast and some people are now on their rooftops," Lontoc told AFP.

"The water is now too deep even for big military trucks, so our people are trying to reach them using rubber boats," he said, but added there were only 10 teams at their disposal at the moment.

Lontoc said many thousands of people may be stranded in those villages, although it was too early to determine an exact number.

- People, pigs huddle on high ground -

In Santa Rosa, water buffalo, pigs, goats, dogs, washing machines and furniture lined the sides of a storm-tossed highway, where about 200 residents had been seeking refuge from the floods since Sunday night.

Jun Paddayuman, 27, in shorts and a white singlet caked with mud up to his chest, pointed to his nearby house, where flood waters had risen to the roof.

"The waters arrived suddenly. We did not expect it at all," he told AFP.

Paddayuman said, when the waters first appeared in his house, he waded to the highway carrying his eight-month pregnant wife and leading his three-year-old son by the hand.

Paddayuman said he had seen geese, chicken and dogs being carried off by the rampaging waters.

Nearby, two men pushed pigs placed on top of truck tyre inner tubes in a valiant attempt to save their hog farm from 1.2-metre (four-foot) high flooding.

Wide expanses of rice paddies had disappeared under torrents of knee-deep water throughout the towns and villages north of Manila because of runoff from torrential rain unleashed by Koppu on nearby mountain ranges.

Lontoc, the regional official, said many residents were lulled into complacency because the typhoon had passed north of the region and did not directly strike the low-lying areas.

Koppu initially hit fishing and farming communities on the east coast of Luzon with winds of 210 kilometres an hour, making it the Philippines' second most powerful storm of the year.

By mid-morning on Monday, it was on the far northwest coast of Luzon and nearly out into the South China Sea, with its strongest winds weakening to 150 kilometres an hour, the state weather service said.

But Koppu was still dumping heavy rain and it was forecast to cut back northeast over Luzon and not leave the country until Wednesday.

The Philippines is hit with about 20 major storms a year, many of them deadly.

The most powerful storm ever recorded on land, Super Typhoon Haiyan, hit the Philippines in 2013, killing or leaving missing at least 7,350 people.

Koppu had so far claimed just two lives, partly because the typhoon directly passed through sparsely populated mountain and coastal ranges.

A 14-year-old boy was killed in a district of the capital on Sunday after a large tree was pulled over by the winds and fell on his house.

A 62-year-old woman died after a wall in her house collapsed due to heavy rains in Zambales, a province to northwest of Manila, on Saturday night.

Schools were closed amid stormy weather in Manila on Monday, although the capital was not badly impacted.