Jerusalem (CNN) -- The Syrian opposition is blaming pro-government militia members for the slaying of a prominent Palestinian militant in his house outside Damascus.
He was Hamas member Kamal Hosni Ghanaja, a former deputy of Mahmoud Mabhouh, who was slain in Dubai in 2010, a death many observers blame on the Israeli spy agency Mossad. Mabhouh was one of the founders of Hamas' military wing.
The Local Coordination Committees of Syria, which opposes the regime of Syrian President Bashar al-Assad, said the pro-government Shabiha militia tortured Ghanaja to death and "set his house on fire to destroy the evidence of their heinous crime." The killing comes amid tensions between Syria and Hamas and sectarian strife inside Syria.
Ghanaja, also known as Nizar Abu Mujahid, was killed Wednesday by an "unknown group of men," Hamas said in a statement Thursday. It is investigating the killing and hopes to "expose the perpetrators involved in this heinous crime."
Hamas official Ahmad Yousef said Israel could be behind the attack. "Because of the political and security vacuum on the ground, it will be for Israel's interest to take advantage and conduct something to that extent," he said.
"The only party benefiting is Israel by the assassination of Hamas officials," he said.
But Israeli Defense Minister Ehud Barak said, "it is possible that not only Israel was on the lookout for him."
"He was not one of the greatest saints of our generation," he said.
It is expected that Ghanaja will be buried in Jordan, Hamas sources said.
"The brother Abu Mujahid served his lifetime devoting himself for the path of God in the ranks of the Islamic Resistance Movement, Hamas, and in the service of the Palestinian cause and his people," the group said.
Hamas, which controls the territory of Gaza and opposes the existence of Israel, had long based its political wing in Damascus.
But the movement's senior officials decided to leave Syria as the 15-month-long uprising against the al-Assad regime intensified, leaving a "security vacuum," Hamas' Yousef said.
The Hamas offices remain open in Damascus, and lower-level officials -- some of whom have ties to Syria, such as family -- handle daily business, he said.
Syrian government officials and supporters have resented the forging of closer ties between Hamas senior leaders and other regional rivals, such as Qatar, which is supporting the anti-al-Assad opposition, and Jordan, which has a peace treaty with Israel.
Hamas leaders have discussed setting up its political wing in Jordan.
Jordan's King Abdullah II met with Hamas Politburo Chief Khaled Mashaal and his delegation on Thursday to discuss a range of issues, Jordan's state-run news agency Petra said.
The Local Coordination Committees said the Ghanaja "assassination" is the latest example of Syrian-Palestinian sectarian violence fomented by the government.
The pro-regime militia called Shabiha has been entering Palestinian refugee camps under the guise of "safeguarding the camps" but they "commit murder and engage in kidnapping," the Local Coordination Committees said. It said the regime is recruiting "drug dealers, drug users, and other criminals" into the militia.
The group said the Syria's "rejectionist policies" toward Israel "have only been attempts to enslave the people."
"The Palestinian experiences in the past demonstrate that the Syrian regime views the Palestinian people as mere cards with which to gamble, regionally and internationally. A regime that kills its own people will not shy away from spilling Palestinian blood for the sake of its own survival," the Local Coordination Committees said.
Some estimates say as many as 15,000 people have died in Syria in more than 15 months.
CNN's Saad Abedine, Kareem Khadder and Guy Azriel contributed to this report.