A senior Hamas leader has reportedly been assassinated in the Syrian capital Damascus. The Palestinian group holds Mossad, the Israeli intelligence agency, responsible for the killing.

However, Israeli officials refuted the claims saying Kamal Ghanaja's killing was linked to the rift between Hamas and the Syrian regime, after the Palestinian Islamist movement publicly turned against their long-time ally President Bashar al-Assad in February.

The Local Coordination Committees (LLC), a prominent Syrian opposition group, alleged that the members of the pro-Assad militia, Shabiha, were behind the slaying.

Hamas said Ghanaja was tortured and shot to death by a group of gunmen who forcefully entered his home and seized his files in the Damascus suburban neighborhood of Qudsaya earlier this week.

A group of people entered his home in Qudsaya ... where he was liquidated, a Hamas official told AFP, on condition of anonymity. According to our information, Mossad was behind the assassination.

The official said Ghanaja was a deputy of Mahmud al-Mabhuh, a senior Hamas military commander who was found dead in Dubai in 2010. Mossad was held responsible for al-Mabhuh's death by the Gulf emirate investigators.

A member of the Hamas Political Bureau, Izzat al-Rashak, announcing Ghanaja's death on Facebook on Wednesday, blamed the killing on a treacherous party, adding that Ghanaja's blood would not be wasted.

The Hamas leadership, however, said the case was open to the group's investigation to identify the party behind the deplorable crime.

Though Hamas hadn't officially blamed Mossad for the killing, Israeli defense minister Ehud Barak said the accusation was not necessarily right.

He was not really personally familiar (to me), Barak told Israeli Army Radio on Thursday, as reported by the BBC. According to all the background published, he was no saint and I don't want to add anything or comment about this incident.

Syrian opposition LLC said Ghanaja was killed by Syrian pro-regime forces since they were the only ones who knew Ghanaja was in Damascus.

He was visiting Syria and nobody knew he was in the country apart from the security services who gave him permission to enter, Hifawi Mohamed, a member of the LCC in the Palestinian refugee camp of Yarmuk in Damascus, told AFP. The way the body was mutilated and the attempt to burn the house are all methods that point to the involvement of the security forces.