The IDF and Shin Bet (Israel Security Agency) have arrested a Hamas terror cell that was operating in the West Bank and was behind a shooting attack last month in the southern Hebron Hills which killed policeman Shuki Sofer, it was released for publication on Monday.Sofer was killed and two other policemen were injured on June 14 in the attack that took place on Road 60 near the settlement of Otniel.RELATED:Palestinian gunman murders policeman in West Bank ambush7 nabbed for cab-driver murderA week later, the Shin Bet arrested a number of Hamas operatives in their twenties who live in the village of Dir Zamat. Some of them had served previous prison sentences in Israel. The Shin Bet revealed in the investigation that the Hamas operatives had several years ago established a terror cell that had stockpiled weaponry hidden in nearby mountains to use in attacks. Among the weaponry found were three Kalashnikov rifles that were used by the perpetrators of the attack in June.IDF sources said that Hamas was continuing to try and reestablish its terror infrastructure in the West Bank but was encountering difficulties due to continued IDF operations in the area as well as increased activity by Palestinian Authority security forces.The cell members held training sessions throughout 2009 following which they decided to target Israeli cars on Road 60. They scoped out the road and noticed Sofer's police vehicle, which traveled the road daily in the early morning hours.On June 14, the terrorists laid an ambush for the police car and at 7:15 as the vehicle approached the village of Dir Razah, three members opened fire, killing Sofer. The group then fled the scene, set on fire the car they had used to get to the ambush point and hid their weapons. During the investigation, the cell members surrendered their weapons and reenacted the shooting.One of the leaders of the cell told how just two weeks before the attack he had accompanied his daughter to Hadassah Ein Kerem Hospital in Jerusalem where she underwent surgery to remove a tumor from her eye. The surgery was funded by an Israeli organization.The group also planned to carry out additional attacks, including to kidnap an Israeli citizen or IDF soldiers. They carried out a number of surveillance missions in the Gush Etzion settlement bloc area and purchased kippot, as well as a wig, that they planned to use to carry out their plot.