BAGUIO, Philippines – American military helicopters ferried tons of aid Sunday to a northern Philippine mountain region facing shortages of food, gasoline and coffins after back-to-back typhoons killed more than 600 in the country.

Four Marine CH-46 helicopters flew to Baguio city, which along with nearby provinces was devastated by storm-triggered mudslides that have blocked three key access roads to the area, isolating the upland region in recent days.

Workers with bulldozers partly cleared one road Sunday, allowing cars but not relief trucks to pass, disaster-response agency spokesman Lt. Col. Ernesto Torres said.

The U.S. military was responding to a request from the Philippines to help deal with the aftermath of two major storms since Sept. 26. Tropical Depression Parma blew out of the country's mountainous north late Saturday, allowing U.S. troops to start airlifting food aid to Baguio.

About 700 Marines and sailors were on hand to help out, said Marine Capt. Jorge Escatell, a U.S. military spokesman.

The helicopters flew to northern San Fernando township, where they picked up about 10 tons of food that were delivered to Baguio.

The floods and landslides killed at least 53 people in Baguio, a summer tourist destination 130 miles (210 kilometers) north of Manila known for its cool climate. Rescuers continued to dig through a huge mound of mud in Crescencia village in search of more than 10 residents who were still missing, Baguio police chief Agrifino Javier said.

While the weather has cleared, the city of more than 300,000 people faced dwindling food and gasoline supplies. President Gloria Macapagal Arroyo flew in by helicopter Sunday to check the situation.

"There is nearly zero gasoline supply now, and we're running low on food," Javier told The Associated Press, adding many foreign tourists were among those stranded in the city.

Gasoline was being rationed and residents have been urged to calm after panic-buying emptied several stores of canned goods, said disaster-response officer Olive Luces.

In nearby Benguet province, police and volunteer gold miners pulled more bodies overnight from houses buried by mudslides late Thursday and early Friday, bringing the province-wide death toll from Parma to 175. At least 20 people remain missing, provincial police chief Loreto Espineli said.