IDF troops killed four Palestinians in clashes in the West Bank on Saturday, including three terrorists killed when troops opened fire at their vehicle, Palestinian and Israeli officials said. Palestinian security officials said the three were ambushed by undercover IDF troops in Jenin, a northern West Bank town known as a stronghold of armed Palestinian groups. They said the dead operatives included two members of the Al Aksa Martyrs' Brigades, a violent group with ties to Palestinian Authority Chairman Mahmoud Abbas's Fatah movement, and a member of the Islamic Jihad organization. There were no other occupants in the car. The IDF said a special unit operating in Jenin came under fire from the car. It said the troops returned fire, hitting the vehicle. Earlier Saturday, several gunfights broke out between troops and Palestinians, while the army was searching the West Bank village of Kafr Dan for suspected terrorists. Palestinian security officials said, Mohammed Said Abed, 22, a Palestinian police officer who was shot dead by troops as he stood on his roof. The army said troops were repeatedly attacked by terrorists during the raid, and the soldiers fired on a man armed with a rifle standing on a roof. Meanwhile, the IDF has declared a full closure on the West Bank and the Gaza Strip, to remain in effect until after Independence Day (Monday). IDF officials stressed that its liaison office would allow Palestinians to cross into Israel via checkpoints in cases deemed "exceptional." Likewise, representatives of international organizations, medical personnel, and religious officials will be allowed to pass the borders, Israel Radio reported. On Friday, two border policemen were lightly wounded after left-wing protesters pelted them with stones in the West Bank village of Bil'in, near Ramallah. Some 200 Palestinians, Israelis and foreigners gathered in the village for the weekly protest against the building of the security fence, despite the area being a closed military zone. One of the wounded men was taken to the hospital for medical treatment, and the security forces took measures to disperse the crowd. Elsewhere on Friday, stones were hurled at an Israeli bus near Kalandiya, south of Ramallah in the West Bank. No one was hurt, but the bus sustained damage. IDF troops were conducting sweeps in the area to locate the perpetrators.