The killing by Nusra Front, an al-Qaeda-linked Sunni armed group, of a Lebanese security officer has prompted protests by his family members and supporters in eastern Lebanon.

Saturday's protests came a day after a video was posted online from an account affiliated with Nusra Front, announcing that Ali Bazzal, the police officer, was executed after Ola Mithqal al-Oqaily, wife of Anas Sharkas, a Nusra Front commander, and their children were not released by Lebanon.

Lebanese authorities earlier this week said they had detained a wife of Abu Bakr al-Baghdadi, leader of Islamic State of Iraq and the Levant (ISIL), in addition to the wife of Shishani.

In the video, Sharkas also cited the case of Saja al-Dulaimi, Baghdadi's wife.

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"If the sisters that were unjustly arrested are not released, then after a short period of time the death sentence will be executed against another prisoner we hold," Sharkas, who used the nom de guerre Abu Ali al-Shishani, said.

"We will not accept anything but the release of all our women and children ... one of my children is four years old, the second is less than six months old. How dare you arrest them with their mother?"

Al Jazeera's Mysa Khalaf, reporting from Beirut on Saturday, said Bazzal's family and supporters blocked several roads in the Bekaa Valley in eastern Lebanon on Saturday in protest against the killing while the army deployed in numbers to the area.

More than two dozen members of the Lebanese security forces are being held in captivity by Syrian fighters.

The Lebanese army had confirmed the arrest of Shishani's wife and her brother on December 3, in what could be seen as an attempt by the government to obtain leverage in ongoing negotiations over the release of 29 army soldiers held collectively by Nusra Front and ISIL since August.

Syria’s civil war has exacerbated sectarian tensions between Lebanon's Sunni and Shia communities, with regular battles erupting between ISIL-linked groups and the army.

Source: Al Jazeera and agencies