DAMASCUS -The Palestinian Islamist group Hamas accused Israel on Friday of assassinating one of its senior military commanders in a Dubai hotel, but Dubai police said the killing was the work of a criminal gang. Mahmoud al-Mabhouh, an Israeli target since engineering the capture of Israeli soldiers in the 1980s during a Palestinian uprising, was killed on Jan. 20, a Hamas official told Reuters in the Syrian capital Damascus. The Dubai police said a "criminal gang ... was following the movements of the victim before his arrival in the United Arab Emirates". An official statement said most of the suspects had European passports and left the country after the killing. The United Arab Emirates does not have a peace treaty with Israel but has hosted Israeli officials and does business with Israeli companies. There was no immediate comment from Israel. Hamas leader Khaled Meshaal made an impassioned speech to thousands of mourners at Mabhouh's funeral on Friday at the Palestinian refugee camp of Yarmouk on the edge of Damascus. Hamas's green flag covered the body as it was lowered into the grave. Meshaal described Mabhouh as a "great man" who fought the Israelis for 30 years. "I say to you Zionists, do not rejoice. You killed him but his sons will fight you," he said. "God already took our leaders and loved ones, but resistance goes on. Palestine is a blessed land. It will not remain patient." Mabhouh's death lengthens Hamas's list of what it describes as "martyrs", and constitutes another setback for the group in its fight against the Jewish state. Israel has killed dozens of leaders and military figures in Hamas, founded two decades ago as a religious resistance movement against Israeli occupation. "I cannot reveal the circumstances (of the killing)," said Izzat al-Rishq, a member of Hamas's politburo. Rishq said Mabhouh, 50, was an important member of the Izz el-Deen al-Qassam brigades, Hamas's military wing. He said the brigades "will respond (against Israel) in the appropriate time and place". However, Hamas would not let the killing derail efforts to arrange a prisoner exchange deal between Hamas and Israel, which have run into difficulties. Mabhouh, who was born in the Gaza Strip but had been living in Syria since 1989, was killed a day after he arrived in Dubai, Rishq said. A Hamas source in Gaza said Mabhouh was an active commander "until the moment of his assassination". He did not elaborate. Another Palestinian source said Mabhouh was found dead in his hotel room in Dubai. He had barricaded the door of his room with chairs, a standard precaution by a man who believed Israeli intelligence had been after him for 20 years. "It seems that an autopsy was ordered and found traces of poison in his body. Mabhouh was also ill. Hamas controls the information on this," the source said. "He was one of their main military guys, although not a crucial figure," the source added. Mabhouh's brother Fayek told Reuters in Gaza his brother was killed "by strangulation after receiving an electric shock" and two people were involved in the killing. Syria and Iran are the main backers of Hamas, which controls the Gaza Strip.