A man tries to cross a road amidst a strong current along a flooded road in Sta Rosa, Nueva Ecija.

Heavy rain deepened flood misery in farming and mountainous regions of the northern Philippines on Tuesday, after the latest typhoon to hit the storm-ravaged nation killed at least 22 people.

Koppu had weakened into a tropical storm and moved into the South China Sea by Tuesday morning, but its huge rain band ensured downpours across swathes of the sodden north where tens of thousands of people were displaced.

“The waters rose really fast, luckily we were rescued,” Lourdes Gatmaitan, 64, told AFP after sleeping at a basketball court being used as an evacuation centre in Cabanatuan, a town about three hours’ drive north of Manila, the capital.

Koppu, the second strongest storm to hit the Philippines this year, had impacted nearly 300,000 people across the main island of Luzon, the government’s disaster management agency said.

Twenty-two people were killed in floods, landslides and boat accidents, as well as by flying debris, according to an AFP tally based on confirmed figures from national and local authorities.

Floods as high as rooftops had covered some of the nation’s most important rice and corn farming regions in the flat plains north of Manila that are either side of a giant mountain range.

While the water had subsided on Tuesday in areas closer to the ranges, such as in Cabanatuan, the flooding had moved downstream to other farming towns.

More than 200 villages in the farming regions were flooded on Tuesday, with some areas more than one metre (three feet) under water, according to a report from the local civil defense office.

And heavy rain continued over the Cordillera mountain range, meaning more water was expected to flow down.

Weather forecasters also warned that Koppu would cut back onto the far northern edge of Luzon on Wednesday morning after picking up more water in the South China Sea.

The Philippines endures about 20 major storms a year, many of them deadly.

The islands of the Southeast Asian archipelago are often the first major landmass that the storms hit after emerging over the Pacific Ocean.

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

Related articles across the web

• Philippines leader pokes fun at Beijing's South China Sea claims, praises Japan
• Does Thailand Border The Pacific Ocean
• Philippines: South China Sea not on APEC Agenda
• China ignores U.S. objections, continues to seize control of strategic sea lanes
• Turnbull weighs in on South China Sea
• China says 'extremely concerned' by US comments on South China Sea
• China says "extremely concerned" by U.S. comments on South China Sea
• Why Chinese Nationalism Could Impact the East and South China Seas VERY Differently
• New Australian PM urges Beijing to cool tensions in South China Sea
• China Land Reclamation Threatens Marine Life In South China Sea