Israeli security forces uncovered what they are calling the largest illegal weapons factory ever discovered underneath a Palestinian home in Hebron overnight Sunday.

According to the Israel Defense Forces (IDF), security forces discovered more than 100 Carl Gustav m/45 barrels, Russian 7.62 sniper rifles and M16 rifle parts with assembly instructions. Forces also seized 15 lathes (a machine for shaping metal) and other production materials used for making illegal homemade weapons.

The IDF deemed the discovery “the biggest weapons factory ever discovered in the West Bank,” Yedioth Ahronoth reported.

The raid, which involved hundreds of soldiers from several IDF units and the Israeli Border Police, is part of an ongoing campaign by security forces to uncover and destroy illegal weapons production facilities in the West Bank that have been used in terror attacks against Israel.

Security forces seized the weapons from the facility and arrested two of the factory’s owners, a father and son, who were given to the Shin Bet security agency for interrogation. During an initial interrogation, the father claimed the facility, which sat underneath his home, was producing farming equipment.