Wide areas on the southern island of Mindanao and in the eastern part of the archipelago from the Bicol region to Samar and Leyte islands were inundated, said Glenn Rabonza, head of the government's disaster agency.

'We're experiencing an unusual heavy downpour brought by the tail-end of the cold front,' Mr Rabonza told reporters, adding many areas have been submerged under 1.2-2 metres of floodwaters.

Mr Rabonza said about 20 people had drowned in swollen rivers or been buried in landslides while 63,000 families or slightly more than 300,000 people had to leave their homes because of the freak weather conditions.

Local officials and church leaders on Mindanao, the hardest hit area, appealed to the president and non-government agencies to send food, potable water and blankets to more than 115,000 people displaced.

'We don't have enough food despite donations coming in from private groups and individuals,' said Mr Constantino Jaraula, mayor of the southern port city of Cagayan de Oro, adding the supply may last only four days.

'Every hour the number of affected families increases. We're appealing for help.'

Landslides and flash floods are common across the Philippines during the monsoon months between May and October.

Officials said they were surprised by the heavy and continuous rains at this time of the year. -- REUTERS