By Jeffrey Heller JERUSALEM, Nov 21 (Reuters) - Palestinian militants in Gaza fired rockets into an Israeli border town on Tuesday during a visit by the U.N. high commissioner for human rights, critically wounding one person, witnesses and ambulance workers said. The commissioner, Louise Arbour, was unhurt in the attack, said Christopher Gunness, spokesman for the Office of the U.N. Special Coordinator for the Middle East Peace Process. "They (the rockets) landed a few hundred yards away from where we were," said Gunness, who accompanied Arbour on the visit to Sderot, a town often targeted by militants in Gaza. "She was in a car but the delegation had parked very briefly when we heard very loud explosions. There were two plumes of smoke," he said. The Magen David Adom ambulance service said a factory worker, described by media reports as a man in his 40s, was critically wounded. The armed wing of the Palestinian militant group Hamas said it launched two makeshift rockets at the town. The salvo landed shortly after Israeli troops killed a Hamas gunman in northern Gaza. Arbour, a Canadian, arrived in Sderot after a visit to the Gaza Strip. She is on a five-day tour of the Palestinian territories and Israel. Gunness said that Arbour had made the point "very, very forcibly" in a conversation with Palestinian President Mahmoud Abbas that he should exercise as much of his authority as possible to try to put an end to the Qassam rocket attacks. "The position of the High Commissioner is that Qassam rockets are illegal under international law. The reason is that they are not accurate and (those launching them) cannot make a distinction between combatants and non-combatants," he said by telephone from Sderot. GAZA RAID Earlier in the day, Israeli troops and tanks launched a deep raid against a Palestinian militant stronghold in the Gaza Strip, killing a gunman during clashes in which an elderly woman also died, witnesses and hospital officials said. Hospital officials named the militant slain in Gaza City's Zeitoun district as Aiman Hassanein, a senior member of the governing Hamas faction. Witnesses said he was killed during an exchange of fire and that his brother was detained by troops. The officials said it was not immediately clear who fired at the 70-year-old woman killed in the violence. An Israeli military spokeswoman confirmed that an operation was under way in Zeitoun but did not give further details. Israeli forces also entered the nearby refugee camp of Jabalya as well as Beit Lahiya, a northern Gaza town that is frequently used by militants to launch cross-border rocket salvoes. Israel renewed its ground operations in Gaza, which Israeli forces and settlers quit last year, after militants captured an Israeli soldier in a deadly border raid in June. Israel has killed more than 370 Palestinians in Gaza, about half of them civilians, since it began the offensive, hospital officials and residents say. Three Israeli soldiers have been killed and a woman in Sderot has died in a rocket strike. Defence Minister Amir Peretz said on Monday Israel would press its fight against Palestinian rocket crews but had no intention of reoccupying Gaza. In Gaza on Monday, Arbour visited Beit Hanoun, a town where 19 civilians were killed on Nov. 8 by Israeli artillery shelling. She spent time at the house of a family that lost more than a dozen members in the shelling, which Israel says was caused by a targeting mistake.
