Russia said on Wednesday it had killed 12 field commanders of Al Qaeda's former Syria affiliate, adding the group's top leader Abu Mohammed Al Jolani had lost an arm and was in a "critical condition".
Defence ministry spokesman Igor Konashenkov said the strike was the result of a special operation to avenge an attack on Russian military police in the so-called Idlib de-escalation zone in Syria on September 18.
"As a result of the strike, the leader of Jabhat Al Nusra Abu Mohammed Al Jolani received multiple serious shrapnel wounds, lost an arm and is in a critical condition, according to several independent sources," Mr Konashenkov said in a statement.
He said 12 field commanders including Al Jolani's security chief were also killed along with some 50 guards.
More than 10 fighters received moderate and serious blast injuries, he said, adding that Sukhoi Su-34 and Su-35 jets were used to target the jihadists.
The Moscow-led forces were able to hunt down the jihadist group using data obtained by Russian military intelligence on Tuesday and struck just when the fighters convened for a meeting.
The Jabhat Al Nusra, or Al Nusra Front, shed its status as Al Qaeda's Syrian affiliate in 2016 and became Fateh Al Sham Front.
Since 2017, it dominates a coalition of jihadist factions called Hayat Tahrir Al Sham.
The alliance controls most of the northwestern province of Idlib after expelling former allies earlier this year.
'Minister of War'
Washington and the UN did not recognise the break from Al Qaeda and retained the jihadists on their terror blacklists.
Over the past months Russia has claimed to have killed several top jihadist commanders.
Russia reported in June its jets had possibly killed the leader of ISIL's Abu Bakr Al Baghdadi during a bombing raid near the ISIL stronghold of Raqqa in Syria and said in July it was struggling to confirm if he was dead or alive.
Earlier this month the ISIL group released an audio recording of what it said was its leader Al Baghdadi.
Last month Russia claimed to have killed several top ISIL commanders in an air strike including the US-trained "minister of war" Gulmurod Khalimov.
Since the assault on Russian military police, Idlib has been the target of heavy air strikes by the Syrian regime and Russia.
The Russian defence ministry said three officers were wounded in the September 18 attack and would be decorated, while the Britain-based Syrian Observatory for Human rights said three Russian soldiers had been killed in clashes with ISIL jihadists.
Idlib province and some adjacent areas form one of four so-called de-escalation zones agreed in May by rebel backer Turkey and government allies Russia and Iran.
Russia intervened in support of the regime of Bashar Al Assad in September 2015 and has helped government forces win back large parts of the country.
Over the past weeks, Russia has lost a number of officers in the conflict including a general, Valery Asapov, believed to be the country's highest-ranking casualty of the Syrian campaign.
More than 330,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests.