An explosion went off Thursday at a West Bank gas station, killing at least two people and wounding 20, police and hospital officials said. Police said welding work at the gas station apparently set off the blast. A nurse at Ramallah Hospital said two people were killed and 20 suffered serious burns. One security official said he had received word of eight people killed, but that report could not immediately be confirmed independently. Sirens were heard across Ramallah as ambulances rushed to the scene.