JERUSALEM, April 15 (JTA) — Members of an elite Israeli army unit operating north of the security zone in southern Lebanon have killed three Hezbollah gunmen and wounded several others in an overnight ambush. No Israeli forces were hurt in the Monday night operation, which was carried out by members of the Egoz unit, a special team established more than two years ago to be used exclusively against Hezbollah fighters in southern Lebanon. According to reports, the Egoz unit crossed the security zone on foot, reaching a village just north of the security zone that had become a springboard for Hezbollah attacks against Israeli and South Lebanon Army forces in the region. The unit opened fire when it came upon a group of Hezbollah fighters. After the firefight, the Israeli troops crossed back safely to the security zone. The head of the Israel Defense Force northern command, Maj. Gen. Amiram Levine, praised the unit and said the operation was intended to send a clear message to Hezbollah to stop activities that violate the cease-fire reached after Operation Grapes of Wrath, the 16-day cross- border offensive Israel launched against Hezbollah one year ago. Under the terms of the cease-fire, both sides agreed not to launch attacks from or on civilian areas in the region. Israeli troops in southern Lebanon are on high alert this week, which marks one year after Israeli shelled the Kana U.N. camp in southern Lebanon, killing at least 91 Lebanese refugees who had taken shelter there. The United Nations condemned Israel at the time, saying that it was aware that refugees were housed at the base. The claim was denied by Israeli officials, who said that IDF artillery units were responding to a Hezbollah Katyusha rocket attack that had been launched from a location near the base.