Israeli troops scouring a West Bank militant stronghold killed a Palestinian teenager and wounded at least 17 others in clashes with stone throwers yesterday, witnesses and medics said. They said a 17-year-old was fatally shot in the chest while confronting troops, who have stepped up searches in Nablus since a bomber killed three off-duty Israeli soldiers and a teenage girl outside Tel Aviv on Thursday. Six of the wounded Palestinians were shot by live ammunition and 11 by rubber bullets in clashes, witnesses and medics said. Israeli troops and tanks have effectively bisected the bustling valley city. A government spokesman said the Nablus sweep was made in response to intelligence alerts of imminent militant attacks. In the West Bank town of Qalqilya, troops threw smoke grenades at demonstrators hurling stones at them in a protest against a concrete barrier Israel erected around the community. Medics said 13 protesters were treated for smoke inhalation. More than a thousand Palestinians were joined by foreign peace activists in the demonstration . The protesters brandished banners urging an end to construction of the "Apartheid Wall". In the West Bank town of Bethlehem, around 50 foreign activists also staged a protest against the barrier. In Cairo, a Palestinian delegation offered a formal apology yesterday to Egyptian Foreign Minister Ahmed Maher for the hostile reception he received from Palestinians earlier this week at the Al-Aqsa mosque in Jerusalem. The delegation, led by senior PLO official Farouq Khadumi, also invited Maher to address the Palestinian legislature and meet President Yasser Arafat. Maher was jostled and harangued by Palestinians on Monday when he went to the mosque during an official visit to Israel, the first by an Egyptian foreign minister since the start of the Palestinian uprising in 2000. **PHOTO CAPTION*** An Israeli soldier throws a concussion grenade at Palestinian demonstrators, during a protest at the concrete separation barrier in the West Bank town of Qalqilya, Saturday, Dec. 27, 2003. (AP Photo/Kevin Frayer)