Israeli citizens have been arrested and indicted for planning an attack against soldiers after the Islamic Movement's northern branch was outlawed in November 2015, the Shin Bet security service said Tuesday.

The suspects are from Be’er Sheva and Kseifa in the south and Kalansua in central Israel. Two of them were arrested in late 2016 and one was arrested at the end of March when he returned to Israel from Turkey, the Shin Bet said.

As part of the plan, the three were allegedly given a homemade Carl Gustav submachine gun, known colloquially as the “Carlo,” to use in the attack. The gun has been located and surrendered to security forces.

One of the suspects is Firas al-Omari, a top man in the Islamic Movement's northern branch. According to the Shin Bet, members of the cell asked him to approve their attack plan.

Omari allegedly headed a group, also outlawed, that provided aid to prisoners convicted of security offenses.

“This investigation exposes the part played by ex-prisoners in the service of the Islamic Movement, who conspired, when called upon, to carry out a serious terror operation in identification with the movement,” the Shin Bet said in a statement.

According to the indictment, the suspects planned to attack soldiers at a bus stop or near an army base using a gun, a car or a knife. To this end, one of the suspects was tasked with finding a vehicle to use in the attack.