Defense Minister Shaul Mofaz fired off a warning to Hizbullah on Sunday saying that if attacked by the guerilla group, Israel would respond swiftly and fiercely. "I recommend that Hizbullah keeps quiet and does not try and escalate the situation in the North," Mofaz told reporters during a tour along the northern border. "If communities in the North are attacked, Israel will not sit idly by, but will respond with all the strength at its disposal, as it has done in the past." Palestinian terror groups, Mofaz warned, were in the midst of planning retaliatory attacks to the capture last week of slain Israeli minister Rehavam Ze'evi's killers during an IDF raid in Jericho. On Thursday, the Shin Bet (Israel Security Agency) confirmed it had beefed up security surrounding government ministers and other public figures, fearing terror groups would try to assassinate senior officials in response to the operation in Jericho. The IDF raised the level of alert along the northern border several weeks ago after the army received intelligence information indicating that Hizbullah was planning to abduct soldiers. On Thursday, additional forces were alerted to the North, backed up by helicopters after two suspicious figures were spotted near the border with Lebanon. "Hizbullah is constantly trying to launch an attack along the border," one security official said. "We are doing everything we can to be prepared and to prevent it." Meanwhile, IDF troops thwarted a stabbing attack at the Gush Etzion hitchhiking post near the settlement of Alon Shvut. The army said a Palestinian man aroused the suspicion of soldiers stationed at the junction and that a knife was found in his belongings. Also Sunday, IDF soldiers at a checkpoint near Tulkarm pulled over a Palestinian car and discovered a 13-year-old passenger in possession of a 250-gram pipe bomb. Army sappers destroyed the bomb in a controlled explosion.