MANILA, Oct 1, 2009 (AFP) - A storm gathering strength to the east of the Philippines could develop into a "super typhoon" and dump more heavy rain on areas of the country still reeling from deadly floods, officials said Thursday.

While Typhoon Parma is so far on track to hit the Philippines north of the main disaster zone, the flood-ravaged areas were still likely to suffer rain and high winds, the government's weather bureau said.

"We are dealing with a very strong typhoon, so we should be at the highest level of preparedness," state weather bureau spokesman Nathaniel Cruz said.

"There is a possibility that this will become a super typhoon."

Cruz said the typhoon was expected to slam into the north of the Philippines' Luzon island on Saturday afternoon.

Tropical storm Ketsana dumped the heaviest rainfall in more than 40 years over Manila and surrounding areas on Saturday, claiming the lives of at least 277 people and affecting more than 2.5 million others.

Typhoon Parma is likely to bring less than half the rains of Ketsana, but it would still compound flooding in Manila where some eastern areas remain underwater as authorities struggle to clean up debris, Cruz said.

"Saturday will be critical, especially in Metro Manila," Cruz said, as he called on the public to be alert and immediately leave their homes if told by local officials.

The government defines a super typhoon as one with winds reaching 175-200 kilometres per hour (108-124 miles) and with the potential to cause heavy damage.

Already packing gusts of up to 185 kilometers per hour, Parma was last monitored at 650 kilometers (400 miles) east of Borongan town on the eastern island of Samar at dawn.