Twenty Arab Israelis have been arrested in a joint Shin Bet (Israel Security Agency) and Israel Police operation on suspicion of conducting weapons deals with a terror organization, the Shin Bet announced Sunday. The Haifa District Court served indictments against six of the men on Sunday. The six suspects, from Kafr Kara and Jisr e-Zarka, are suspected of conducting weapons deals with Tanzim operatives in the West Bank. The principal suspect in the case, Hamza Masri, 24, is accused of trafficking weapons and munitions with Shahar Hanina, 41, head of the terror group in Kalkilya. Among the charges detailed in the indictment, it is alleged that in 2005 Masri acquired a pistol for Hanina, as well as a 15-kilogram bag of potassium for use in preparing explosives. Masri was fully aware that the potassium was intended for use by the terror group, read the indictment. Masri was arrested later that year and warned about his ties with Hanina. However, upon his release from custody, Masri allegedly resumed his contacts with the Tanzim head, purchasing tens of thousands of dollars' worth of weapons and munitions for Hanina, including an M-16, a hunting rifle and a laser sight for an M-16. Masri is additionally suspected of buying weapons from Hanina and then selling them to Israelis for drugs and money. The Shin Bet said that in recent years there have been several cases of weapons deals between Israeli criminal gangs and terror operatives in the West Bank and Gaza. In a statement, the Shin Bet said: "Security forces have been conducting a protracted war on weapons thefts, including from IDF bases, and weapons sales to terror groups in the Palestinian territories. There are close ties between terror operatives in the territories and criminals holding Israeli citizenship. These transactions are used by the terror groups for the purpose of perpetrating terror attacks against Israel."