Israeli helicopter gunships have fired missiles at Shaikh Ahmad Yasin as he left a mosque before dawn, killing the Hamas leader and at least six other people. A Reuters reporter who rushed to the scene on Monday after hearing three loud explosions found the blown-up remains of Yasin's blood-soaked wheelchair. One witness who lives near the mosque told reporters what happened moments after the first explosion. "I looked to see where Shaikh Ahmad Yasin was," he said. "He was lying on the ground and his chair was destroyed. People there darted left and right. Then another two missiles landed." Yasin's body was evacuated to Gaza City's Shifa hospital. At least six people died in the attack including at least two of Yasin's bodyguards, and 10 more were wounded. Shaikh Yasin's two sons were moderately hurt. The Israeli army later admitted it had carried out the killings. **'The shaikh is dead'*** "The shaikh is dead. The sheikh is dead," sobbed Hamas resistance fighters who gathered at the scene. Israel has said it would step up operations to track and kill Palestinian resistance fighters after a string of bombings, including one at a strategic port last week in which 10 people were killed. Thousands of Palestinians, many in tears, poured into the streets and fighters fired into the air. Palestinian Authority officials condemned the attack. "This is a crazy and very dangerous act. It opens the door wide to chaos. Yasin is known for his moderation and he was controlling Hamas and therefore this is a dangerous, cowardly act," said Prime Minister Ahmad Quraya. Yasin, who was in his late '60s, has been confined to a wheelchair since an accident as a teenager that paralysed him. He is also partially blind. Yasin was sentenced by Israel in 1989 to a life term for founding Hamas and inciting Palestinians to attack Israelis. But Israel released him in 1997 as a goodwill gesture to Jordan's King Husayn after an attempt to assassinate Hamas leader Khalid Mashal in Jordan failed. **Marked for death*** An Israeli minister said that Yasin had been "marked for death". "Yasin and the others were behind the terror framework in the Gaza Strip," Deputy Defence Minister Zeev Boim told Israel Radio. Israeli Prime Minister Ariel Sharon personally supervised the attack on Yasin, Israeli public radio reported. Sharon had given the green light to Yasin's assassination and supervised the operation, the radio said. Hamas resistance fighters vowed to "bring death to every house" in Israel in revenge. "Sheikh Ahmad Yasin rest in peace. They will never enjoy rest. We will send death to every house, every city, every street in Israel," Hamas resistance fighters shouted through loudspeakers in the streets of Gaza City. **PHOTO CAPTION*** Sheikh Ahmad Yassin. (Al-Jazeera)