A super typhoon sweeping towards the Philippines on Saturday was intensifying and could have a "potentially catastrophic" impact, the state weather forecaster warned, with millions of people at risk from storm surges.

Tropical cyclone Man-yi has strengthened into a super typhoon, threatening to bring intense rains and high waves on the Philippines’ main island that’s still reeling from a string of storms in recent weeks.

The Philippines evacuated tens of thousands of people from their homes and cancelled dozens of flights on Saturday, as a super typhoon threatened to unleash heavy rains and powerful winds that could trigger floods and storm surges.