The spokesman for Al-Qaeda's Syrian affiliate, Al-Nusra Front, his son and 20 other jihadists were killed in air strikes Sunday in the northeast of the country, a monitor said.
"Abu Firas al-Suri, his son and at least 20 jihadists of Al-Nusra and Jund al-Aqsa and jihadists from Uzbekistan were killed in strikes on positions in Idlib province," Syrian Observatory for Human Rights chief Rami Abdel Rahman told the AFP news agency.
It was not immediately clear if the raids were carried out by Syrian regime warplanes or their Russian allies.
Abdel Rahman said Suri was meeting with other leading jihadists in Kafar Jales when the raids struck and that two other Al-Nusra and Jund al-Aqsa targets were also attacked.
A temporary ceasefire between government forces and rebels has largely held since February 27, but it does not cover Al-Nusra Front and the Islamic State (ISIS) group.
In fact, the head of Al-Nusra, Mohammad al-Jolani, called on the group’s members to reject the ceasefire and instead intensify attacks on the regime.
On Wednesday, a drone strike near ISIS's de facto Syrian capital, Raqa, killed a jihadist commander, according to the Observatory, in the latest in a series of blows to the jihadists in recent weeks.
Al-Nusra Front and ISIS, in addition to fighting the so-called moderate rebels and the Syrian regime, have also at various times during the civil war fought each other.
Last November, Al-Nusra and ISIS temporarily agreed to work together.
AFP contributed to this report.