Foreign Minister Avigdor Liberman lashed out at the hundreds of Israeli Arab demonstrators who clashed with police at Umm el-Fahm junction on Friday during a protest against IDF efforts to track down three kidnapped teenagers in the West Bank.Liberman, who heads the Israel Beiteinu party, said that the demonstrators "should be treated as terrorists in every sense of the word."The foreign minister said he would urge Public Security Minister Yitzhak Aharonovitch to "act with determination and speed in arresting the inciters so that they could be prosecuted to the full extent of the law.""Israel Beiteinu will demand that the government discuss the dangerous radicalization of the Israeli Arab leadership and to deal with it in a thorough, severe matter," Liberman said.Hundreds of Israeli Arabs and pro-Palestinian supporters angry over Israel's military operations in the West Bank and Gaza burned tires and staged a demonstration near Umm al-Fahm junction on Route 65.Police massed forces in the area in an attempt to restore order after demonstrators hurled stones in their direction.The public security minister reacted angrily to reports that some of the demonstrators chanted for more kidnappings of soldiers."These are grievous statements that attest to the radicalization of parts of the Arab public," Aharonovich said. "The inciters will be dealt with to the fullest extent of the law and in accordance with the law. We will not allow these events to interrupt the daily lives of citizens in this country."The authorities knew beforehand that the demonstration was taking place. Earlier Friday, police warned motorists to stay away from the area.The violence had escalated earlier in the afternoon on Friday, but as of the evening hours police have managed to quell the unrest. Hadash MK Mohammed Barakeh was among those demonstrating."This demonstration is a protest against the violence of the IDF and against the illegal arrests and illegal activities of the IDF in the territories," Barakeh said.The demonstrators waved Palestinian flags and chanted "With spirit and blood, we will redeem you, Palestine" and "We will redeem the martyrs." Police vowed to prevent the demonstrators from "harming the routine of Umm el-Fahm residents and endangering motorists."