Hamas announced that leader Kamel Ranaja was killed in his home in Damascus Wednesday night, adding that they suspected the Mossad was behind the assassination, Haaretz reports. But increasingly negative relations between Syria and Hamas, which did not support the Assad government's crackdown on constant civil disorder, may suggest another killer.

Ranaja was a former deputy of Mahmoud al-Mabhouh, a top Hamas official who founded the group's military wing and was assassinated in Dubai over two years ago. Israel was suspected by United Arab Emirates police of carrying out al-Mabhouh's killing, although he was also wanted by the Egyptian and Jordanian governments.

Israel's record of striking Hamas leaders makes it a natural suspect. But other motives and suspects are plausible.

"Practically, it's not reasonable that Israel or a Western country would settle accounts with a man like this, at this stage, in Syria. He's not big enough," former senior Mossad member Rami Igra told the Jerusalem Post. "He's not important enough. To assassinate him would be a very complicated, dangerous operation, and it would be taking a huge chance. I don't see Israel or any Western country willing to take this risk."

As a deputy to al-Mabhouh, Ranaja would have been privy to his former boss' weapons-smuggling contacts, Ely Karmon of the Interdisciplinary Center's Institute for Counter-Terrorism told the Post. Ranaja may have provided weapons to Hamas' allies in the Syrian opposition, particularly the Syrian Muslim Brotherhood, due to the organizations' close ties. In that case, Syria may have exploited chaos in Damascus to carry out a revenge hit.

Karmon also entertained the possibility that Hamas itself carried out a hit on Ranaja, who may have pocketed cash owed to Hamas for weapons smuggling. "We saw this happen with Fatah, when Arafat killed his own operatives in Europe for stealing cash," Karmon said.