MANILA (AFP) - Thousands of critically endangered turtles have been saved from possible extinction after being rescued from terrible conditions in the Philippines, conservationists said Wednesday.

More than 4,000 live freshwater turtles and 90 dead ones were found in a dry concrete pond in a remote warehouse on the western island of Palawan four weeks ago in one of the country's biggest wildlife rescues.

They included 3,831 Palawan forest turtles, a critically endangered species found only in the north of the large island, as well as 160 Asian leaf turtles and 25 Southeast Asian box turtles.

"The turtles were in terrible conditions," said Sabine Schoppe, director of the Philippine Freshwater Turtle Conservation Programme.

The reptiles had apparently been without food or water for about six months, destined for the pet and food markets in Hong Kong and China, Schoppe said in a statement.

Veterinarians worked round the clock over the next few weeks to save the animals and prevent a potential species die-off.

"This number equalled the estimated remaining population of Palawan forest turtle in the wild, hence bringing the species to the brink of extinction," the statement said.

Many of the turtles were in "shocking, sickening" condition, suffering from eye ulcers, dehydration and other health problems, according to the Turtle Survival Alliance, an international conservation group that helped treat the reptiles.

Some 360 of those rescued had since died, according to Schoppe.

About 230 are still being treated, while the rest were released back into the wild, she added.

The owner of the building where the turtles were kept could not be found after the June 17 raid, according to Jennifer Lyn Yap, of the Palawan Council for Sustainable Development.

The Palawan forest turtle, which weighs as much as 3.5 kg is an "aggressive" species that cannot be kept in groups, Schoppe said.

The turtles were transferred by truck to a rescue centre for critically endangered Philippine crocodiles in the provincial capital Puerto Princesa, the only location on the island capable of housing such large numbers of rescued animals.

Trapping or trading in the species is punishable by jail terms and fines.

However, the Palawan provincial government has struggled to prevent poaching in one of the country's most biologically diverse areas.

Wildlife authorities suspect northern Palawan poachers had sold the turtles to a trader who transported them to the other end of the island.

"Our assumption is they would have ended in the Chinese markets, where they are sought after as food or pets," Yap said.