Manila - Philippine President Gloria Macapagal Arroyo Thursday ordered agriculture and health officials to closely monitor an outbreak of an Ebola virus strain in several pig farms in three northern provinces.

Deputy presidential spokesman Anthony Golez said Arroyo wanted agriculture authorities to prevent the Ebola Reston virus from spreading to other pig farms in the country.

Golez, a medical doctor, assured the public that the Ebola Reston virus found in the pigs was not harmful to humans.

"From the epidemiological standpoint, humans have high tolerance for this virus," he said. "Just like any other food, we should make sure that the food we are preparing is cooked properly."

Golez said the Ebola Reston virus dies at 70 degrees Celcius, which is below boiling point.

Agriculture Secretary Arthur Yap said the government had temporarily suspended exports of all pork products from the Philippines until the virus has been eradicated.

"Although the virus does not affect the health of humans, we decided to put on hold all exports," he said. "Let us eradicate first this virus."

Yap said agriculture technicians confirmed that 28 pigs from four piggeries in the northern provinces of Bulacan, Pangasinan and Nueva Ecija had tested positive for the virus during a recent random check.

He said the Bureau of Animal Industry set up pig checkpoints to prevent the transport of contaminated animals.

A total of 42 people who had close contacts with the contaminated pigs had tested negative for the disease, Yap said. (dpa)