A Pakistani army helicopter carrying about 16 people crashed Thursday in a remote northwestern tribal region that has seen sporadic fighting between government forces and foreign militants, police and army officials said. The helicopter went down near Karak, a town in North Waziristan, officials told The Associated Press. Authorities have recovered at least four bodies from the crash site, Inayat Ullah, a police official in Karak, told The Associated Press. He did not know if there were any survivors, but said they believe about 16 people were on board. Another police officer, Naseer Mohammed, said the helicopter caught fire after the crash and that several bodies might still be inside the wreckage. It was not clear what caused the crash. The crash came a day after Pakistan's No. 2 army official, Vice Chief of Army Staff Yousaf Khan, visited the tribal areas to meet with his troops. A senior army official confirmed the helicopter went down at about 10 a.m. but had no further details. He asked that his name not be used. Thousands of Pakistani soldiers have been moved into the region near the border with Afghanistan - particularly North and South Waziristan - in recent months. The two provinces are considered possible hiding places for Osama bin Laden and his top deputy, Ayman al-Zawahri, though there is no hard information on their whereabouts. Several clashes between the army and local tribesman have killed scores of people this year. **PHOTO CAPTION*** Karak city in Pakistan.