Super Typhoon Noru slammed into the Philippines Sunday, battering the heavily populated main island Luzon with strong winds and heavy rain that have forced thousands of people to flee their homes.

The storm was packing maximum sustained winds of 195 kph (121 mph) as it charged toward the archipelago nation after an unprecedented "explosive intensification," the state weather forecaster said.

Noru, the strongest storm to hit the Philippines this year, made landfall in Burdeos municipality on the Polillo islands, part of Quezon province, at 5:30 p.m. (9:30 a.m. GMT).

Videos posted on social media and verified by AFP showed trees swaying wildly as wind and rain whipped across the islands.

The weather bureau issued warnings late Sunday for "serious flooding" in vulnerable areas of the capital Manila and nearby provinces as Noru dumped heavy rain.

"We ask residents living in danger zones to adhere to calls for evacuation whenever necessary," Philippine National Police chief General Rodolfo Azurin said. The Philippines is regularly ravaged by storms, with scientists warning they are becoming more powerful as the world gets warmer because of climate change.

"The winds were fierce this morning," said Ernesto Portillo, 30, who works as a cook in the coastal municipality of Infanta in Quezon.

"We're a bit worried ... We secured our belongings and bought a few groceries so we have food just in case."

Noru weakened to a typhoon as it swept across central Luzon. It is expected to enter the South China Sea on Monday and head toward Vietnam.

"Typhoons are like engines – you need fuel and an exhaust to function," said weather forecaster Robb Gile.

"In the case of Karding, it has a good fuel because it has plenty of warm waters along its track and then there is a good exhaust in the upper level of the atmosphere – so it's a good recipe for explosive intensification," he added, using the local name for the storm.

The storm hit about 100 kilometers northeast of Manila. Emergency personnel braced for the possibility of strong winds and heavy rain battering the capital, home to more than 13 million people.

Forced evacuations were underway in some high-risk areas of the metropolis, including impoverished communities living in flimsy shacks along rivers.

Gloria Perez, 68, was part of a group sheltering in modular tents set up on a covered basketball court. "I evacuated the house where I'm living in because I'm scared, the flood there gets really high," Perez told AFP. "I don't want a repeat of what happened to me before."

Calm before the storm

Noru came nine months after another super typhoon devastated swathes of the country, killing more than 400 people and leaving hundreds of thousands homeless.

More than 8,300 people fled their homes before the latest storm hit, including residents in several municipalities in Quezon, disaster officials said.

In the neighboring province of Aurora, residents of Dingalan municipality were forced to seek shelter. "People living near the coast have been told to evacuate. We live away from the coast so we're staying put so far. We're more worried about the water from the mountains," said Rhea Tan, 54, a restaurant manager in Dingalan.

The weather bureau warned of dangerous storm surges more than three meters high along the coast of Aurora and Quezon, including the Polillo islands, along with widespread flooding and landslides as the storm soaks the region.

It could topple coconut and mango trees, and cause "severe losses" to rice and corn crops in the heavily agricultural region, while inundating villages. The coast guard reported more than 2,500 people had been left stranded by ferry cancellations as vessels took shelter ahead of the storm.

Dozens of flights in and out of Manila were also canceled. School classes and nonessential government services have been suspended for Monday.

The Philippines – ranked among the most vulnerable nations to the impacts of climate change – is hit by an average of 20 storms every year.