MANILA (Reuters) - The Philippines put troops on alert on Wednesday and prepared food and medical supplies as it warned residents and tourists along its eastern coasts to be ready for a super typhoon expected to land some time in the next 72 hours.

Typhoon Maysak is currently a category five storm - the highest rating - hovering over the Pacific Ocean with winds gusting as high as 250 kmh.

It is expected to weaken once it hits the central or northern parts of the main Philippine island of Luzon on Saturday or Sunday, the weather bureau said, as the Philippines celebrates the Easter long weekend. "This is very strong and it will maintain its strength as it nears, although we expect that the typhoon will weaken," Esperanza Cayanan, an officer at the weather bureau, said in a televised briefing. "But this will still be typhoon intensity so it will bring strong winds when it makes landfall on the eastern coast."

British-based Tropical Storm Risk said Maysak would likely weaken to a category 2 typhoon, with maximum winds of up to 175 kmh, when it hits land.

The typhoon could damage rice and corn crops in central and northern areas of the Philippines, although damage is likely to be minimal because the major harvest of the national staple rice was finished around February.

Mr Alexander Pama, executive director of the national disaster agency, said the biggest challenge for the authorities would be keeping foreign and Filipino tourists travelling to northern provinces for the weekend safe when Maysak makes landfall.

Thousands of Filipinos have already begun travelling to the provinces and popular tourist spots before public holidays begin on Thursday. "Because of our holiday mode, some of us may not give proper attention to the warnings," Mr Pama said.

Maysak was moving north-west and was about 1,220km from the eastern town of Guiuan in the central Philippines early on Wednesday.