Philippine President Benigno Aquino put state relief agencies on alert Tuesday and warned those living near the coast to get ready to flee as the country braced for a strong tropical storm.

With winds of 135 kilometres (83.8 miles) per hour and gusts of up to 105 kilometres (65.2) per hour near the centre, the coast guard barred fishing vessels and small ships from going out to sea ahead of Tropical Storm Songda.

As the storm is not forecast to hit the north-eastern part of Luzon island until late Thursday, Aquino believes there is enough time to prevent casualties, his spokesman Edwin Lacierda said in a statement.

"President Aquino is closely monitoring the preparations for the coming of (Songda) and has instructed the concerned agencies to do all that is possible to minimise loss of life and damage to property," Lacierda said.

"We appeal to those low-lying and landslide-prone areas to cooperate with local authorities if and when they are asked to evacuate," he added.

Heavy rains are expected across the Philippines' central islands from Wednesday, which could cause flooding and landslides, the weather bureau said.

It forecast between 20 and 40 millimetres (0.79-1.57 inches) of rain an hour, compared to the 56 millimetres an hour dumped by Tropical Storm Ketsana in 2009.

That storm caused Manila's deadliest flooding in decades and killed more than 400 people.

An average of about 20 storms and typhoons, some of them deadly, slam into the Philippines from the Pacific Ocean every year.

Early this month, tropical storm Aere left 31 people dead after pummelling Luzon island.

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