BAGUIO, Philippines - U.S. Marine CH-46 helicopters loaded with rice, sardines, and drinking water flew yesterday into this stricken Philippine mountain city where supplies are running short after landslides blocked roads and buried dozens of residents.

Three days after heavy rains sent tons of mud and rock cascading down hillsides in Baguio, rescuers were still digging for survivors. Panic buying of canned goods emptied stores in the city, and authorities were forced to ration gasoline.

"There is nearly zero gasoline supply now, and we're running low on food," said Agrifino Javier, the city's police chief.

But as Tropical Depression Parma blew out late Saturday after drenching the country's north for a week, the overwhelmed government, helped by the U.S. military, was able to step up relief efforts.

Back-to-back typhoons in two weeks have killed 600 people in the northern Philippines. Hundreds of thousands are displaced from their homes, and the damage runs into hundreds of millions of dollars.

Baguio lies in a swath of the north where Parma's rains have left 276 people dead. At least 53 of them died in Baguio, a tourist destination, 130 miles north of the capital Manila, known for its cool climate and winding, pine tree-lined roads.

Floods and mudslides have blocked three key roads to the area, isolating the upland region for three days, said Marine Capt. Jorge Escatell, a U.S. military spokesman.

Yesterday, four twin-rotor CH-46 Sea Knight helicopters flew supplies to Baguio.

In all, 700 U.S. Marines and sailors on land and at sea are helping with the relief effort.

Before Parma struck, the 31st Marine Expeditionary Unit, based in Okinawa, Japan, was helping in the aftermath of Tropical Storm Ketsana, which caused the worst flooding in more than 40 years in and around Manila on Sept. 26. That storm killed 337 people in and near the capital.

President Gloria Macapagal Arroyo also came by helicopter to Baguio and ordered officials to hasten efforts to reopen roads. One was partly reopened yesterday, allowing cars but not relief trucks to pass, said Lt. Col. Ernesto Torres, a spokesman for the Philippines' disaster-response agency.

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 remained missing, provincial police chief Loreto Espineli said.