Two residents of Rishon Lezion were under arrest forstealing up to 170 advanced firearms from a secret Israel Weapons Industryplant and selling the arms to underworld criminal organizations, policerevealed on Wednesday."This is a very serious development, which could actively harm our nationalsecurity. These weapons have fallen into criminal hands. I hope the arrestswill go some way towards retrieving the firearms," Ch.-Supt. Tomer Cohen,of the Central District's Central Unit, told The Jerusalem Post."Our priority now is to check whether these firearms have been sold on toterrorists," Cohen added. "The majority of the 170 firearms have beensold to criminal elements, and we are in the process of trying to track themdown," he added.The undercover investigation was launched when police recovered a number ofstolen weapons hidden in a cache in an open field in an Arab town in November 2008. The firearms werethen traced back to the Israel Weapons Industry plant.The Central District's Central Unit activated two undercover agents to monitorthe suspects as they allegedly stole millions of dollars worth of advancedweaponry designated for special army forces, elite Israel Police units, andgovernment security agents.The stolen arms include Galil sniper rifles with silencers, assault rifles withgrenade launchers attached designed for elite Israel Police units, mini-Uzi submachine guns with silencers, and several types of handguns.Some of the sniper rifles have a range of one kilometer. "The majority of the weapons have already been sold," Cohen said. "Theywere taken directly off the production line," he added.The two suspects have been named as Sergey Kirzener, a former Israel WeaponsIndustries (IWI) plant employee, and Sharon Gutin, a man police describe as anunderworld figure who acted as an intermediary between mob weapons buyers andKirzener.Kirzener was tasked with testing the firearms at a firing range in the plant."He would take ten guns away for testing on the range and come back withseven," a police source told The Jerusalem Post.Kirzener was sacked in recent months for disciplinary reasons, but was able tocontinue selling the weapons because he had hidden a number of firearms incaches outside of the plant.A Rishon Lezion magistrate extended the custody of the suspects until January31.A girlfriend of one of the suspects has also been questioned under caution.Police say the arrests came after "a certain breakthrough" was made, butadded that they could not elaborate at this stage.A media gag order prevents publication of certain information pertaining to theinvestigation.