An electrical fire forced a cargo plane's pilots to attempt an emergency landing in a rice field in Pampanga when the aircraft burst into flames, killing three of its six crew, investigators said Thursday. The Russian-made Antonov-12 aircraft was flying from Mactan in the central Philippines and crashed late Wednesday in the field in Mexico, Pampanga, about 22 miles south of Clark airport, the former US air base, said Alfonso Cusi, director-general of the Civil Aviation Authority. Firefighters struggled into the night to put out the flames that engulfed the aircraft after it exploded on impact, ripping the plane into two sections, said police Chief Inspector Carlito Fabro. Villagers managed to rescue three crew members – two Russians and an Uzbek, who suffered bruises and were brought to a hospital in Mexico township, police said. Three other crew were found dead near the cockpit, Cusi said, adding investigators were trying to identify the burned bodies. A police report said they included two Russian ground engineers and a Bulgarian. “They had a technical problem, and a fire broke out inside the plane,” Cusi said. “Their communication signal suddenly got garbled then the plane disappeared in the radar.” Police quoted the Russian pilot as saying that the plane encountered electric circuit trouble about an hour into the flight, and a fire that broke out forced him to make an emergency landing on the open field. The plane was chartered by shipping company UPS Inc. from its owner, Interisland Airlines of the Philippines, police said. The Clark International Airport Corp.'s control tower said it received an emergency call from the pilot around 8:48 P.M., informing them that a part of the plane was on fire. Rene Lising, a villager who witnessed the plane crash, said he saw the aircraft flying very low before crashing. The impact snapped the plane into two parts. Senior Inspector Ronnie Barrera, Central Luzon regional fire chief, said the plane burst into flames after the explosion.