QALQILYA, West Bank, Nov 17 (Reuters) - Israeli troops killed a Palestinian man and wounded 30 others when they opened fire during an arrest raid in the West Bank town of Qalqilya on Friday, residents and the army said. Local hospital staff said the dead man was aged 18. Several people who threw firebombs and stones during clashes with troops were in critical condition. Local residents said the soldiers were attempting to arrest a militant from the governing Islamist group Hamas. An Israeli army spokesman said troops had fired at a group of some 200 protesters who hurled rocks and Molotov cocktails at troops in the central West Bank town. He declined to give details of the raid but said live ammunition had been fired at the troops. Israeli forces often enter Palestinian towns and villages in the occupied West Bank to arrest militants. Residents said troops had surrounded a house and called on the man to surrender. After he failed to emerge from hiding, a bulldozer began to demolish the building to force him to give himself up. In the Gaza Strip, missiles fired from an Israeli helicopter destroyed the home of a Hamas operative, a charity office belonging to the group and a police force office belonging to the group in three separate strikes, local residents said. There were no reports of casualties. It was Israel's latest strike against militant targets since it began an offensive in Gaza in June after gunmen from the area abducted an Israeli soldier in a raid inside the Jewish state. Israel has killed more than 320 Palestinians in Gaza, about half of them civilians, since it began its assault. The residents said the house of the Hamas man was close to the home of Palestinian Prime Minister Ismail Haniyeh. His house was not damaged. The army confirmed helicopters had struck at targets used by militants in the coastal territory.