Abu Hammam al Shami was among those killed in the strikes against al-Nusra, al Qaeda's largest affiliate in Syria
, the source said. Syria's state news agency SANA also reported al Shami's death.
The special operation that took place in Hobait, in Idlib province, was part of a wider effort by Syrian forces to destroy areas believed to be gathering points for al-Nusra militants around the province, according to SANA.
According to a 2014 al-Nusra video, al Shami joined the group after years of training in Afghanistan and Iraq.
Also killed in the northwestern province of Idlib was a senior Saudi operative in the group, the source said.
There were initial indications that al-Nusra leader Abu Mohammed al Jolani was wounded in one of the strikes, the source said Thursday. But on Friday, the source told CNN the latest assessment of Syrian intelligence was that al Jolani was not injured.
The strikes took place in the towns of Salqin and Hobait, both near the city of Saraqeb in Idlib. One strike targeted a meeting of senior al-Nusra Front leaders; the other was on a home being used as a base, the source said.
A spokesman for the U.S.-led coalition that is hitting ISIS
targets in Syria said its planes weren't involved.
"Within the last 24 hours, we have not conducted any airstrikes within 200 miles of the province of Idlib," the spokesman said earlier Thursday.
Al Shami was featured in a March 2014 video released by al-Nusra Front, in which he discussed his failed attempt to mediate between his militants and ISIS after rising tensions between the groups.
The video included a biography by the group of al Shami, which was translated by the Long War Journal. It said that in the late 1990s, al Shami traveled to Afghanistan, where he was trained in a camp run by Abu Musab al Suri, a veteran Syrian jihadi strategist.
Al Shami then trained in al Qaeda camps, where he met one of the 9/11
hijackers and personally swore allegiance to Osama bin Laden
. By the time of the 9/11 attacks, al Shami had started to train recruits in Afghanistan and was named as the head of the Syrian jihadist contingent within al Qaeda.
After the fall of the Taliban, he fled Afghanistan with senior Egyptian al Qaeda operative Sayf al Adel, the group said in the video. Al Shami began operating in Iraq
, where he began working with al Qaeda in Iraq founder Abu Musab al-Zarqawi, conducting training for the group during the Iraqi insurgency, the al-Nusra video stated.
In 2005, al Shami returned to Afghanistan for a short period, at the request of al Qaeda's leadership.
When he got to the Afghanistan-Pakistan region, one of bin Laden's top deputies, Attiyah Abd al Rahman, tasked al Shami with leading al Qaeda efforts in Syria, but he was arrested as he traveled through Lebanon, according to the video, and was detained for five years. After being released, he found his way to Syria, where he joined al-Nusra, the group said.