The Nusra Front, al-Qaeda's wing in Syria, has killed one of ten Lebanese soldiers it had been holding in captivity, Lebanese security sources and a statement on Twitter said.
The statement, posted on Friday by an account affiliated with the group, said the soldier had become "the first victim of the intransigence of the Lebanese army".
The Nusra Front hopes to exchange the soldiers for members of the group being held in Lebanese prisons. They released six soldiers last month as a gesture of good faith for negotiations.
Earlier on Friday, two Lebanese soldiers were killed by a roadside bomb near the Syrian border, security sources said, in the first such attack since fighters from Syria launched a deadly incursion last month.
Three soldiers were also wounded by the bomb, which hit a military personnel carrier near the town of Arsal, where the army battled fighters affiliated to ISIL and other groups for five days last month.
After the bombing, soldiers raided houses in the town in search of fighters, security sources said. The army later used "heavy weapons" to target rebel positions around Arsal, the state news agency reported.
Lebanon has struggled with spillover from neighbouring Syria's conflict.
Source: Al Jazeera and agencies