Schools were closed and thousands of people were evacuated across the north of the Philippines' main island of Luzon in preparation for what was expected to be the strongest storm of the year, rescue and relief officials said.

The northeastern province of Isabela was the first to feel the typhoon's fury today morning although there were no immediate reports of casualties, chief government weatherman Graciano Yumol said.

"The natural hazards are taking place. There are landslides in the mountains, we have swells, storm surges and big waves along the coast line, and now we have flood alerts," Yumol said in an interview with GMA 7 television.

As of 8:00 am (0000 GMT) today, the government weather station tracked Megi just off the coast of Isabela, about 320 kilometres (198 miles) north of the capital, Manila.The storm was not expected to hit Manila directly but Yumol warned the city's 12 million residents to remain on alert.

"It will rain here as well so do not lower your preparations," he said.The storm, dubbed a "super-typhoon" by government relief agencies, was moving southwest at 19 kilometres per hour, packing gusts of up to 260 kilometres per hour, the government weather station said.

Megi was expected to cut across the northern part of Luzon throughout today, then exit out to the South China Sea on Tuesday, the weather station said