MANILA, October 9, 2009 (AFP) - Thousands of people were stranded amid worsening floods in the northern Philippines on Friday after heavy rains forced authorities to release water from an overflowing dam, officials said.

Local officials made urgent pleas for rubber boats and helicopters to rescue those stranded in Pangasinan province, deepening the crisis for the Southeast Asian nation after nearly two weeks of floods claimed more than 300 lives.

Television reports said that about 60 percent of Pangasinan, including about 30 towns, were flooded with waters reaching as high as the second storeys of buildings.

Even heavy trucks that were sent to rescue people could not make it through the rising floodwaters.

The problem was compounded by water being released by a dam that was already on the verge of bursting, said Pangasinan provincial administrator Raffy Baraan.

"We are trying to do our best but we need choppers and rubber boats," Baraan said.

About a thousand people were reportedly stranded in a shopping mall in Pangasinan but rescue boats had been sent to fetch them, Baraan said.

The mayor of Alcala town in Pangasinan, Manuel Collado, said his residents were in dire need of quick help.

"There are still stranded people. We have village officials trying to rescue them, using bamboo rafts," Collado said in a television interview.

"We called the national government for help but they said all their rubber boats are already out so we are building these bamboo rafts in the meantime."

The heavy rains were brought about by tropical depression Parma, which had been hanging over the northern Philippines for almost a week after initially arriving as a typhoon on October 3.

Parma had claimed 25 lives over the past week, with 39 people missing, the civil defence office said.

Parma hit the Philippines exactly one week after tropical storm Ketsana dumped the heaviest rains in more than four decades on the nation's capital, Manila, killing more than 300 people.