BEIRUT -- Syrian state-run TV reported Friday that the leader of a powerful al-Qaida-linked rebel group has been killed -- a claim that, if confirmed, would be a huge blow to fighters trying to topple President Bashar Assad. At least one rebel commander denied the report.
Questions remained over whether Abu Mohammad al-Golani, head of Jabhat al-Nusra, or the Nusra Front, had indeed died. State TV said he was killed in the coastal province of Latakia, but did not say when or give details. Later Friday, it removed the report from its website, without explanation.
The Britain-based Syrian Observatory for Human Rights, which closely monitors fighting in Syria, said senior Nusra Front leaders contacted by activists in Latakia and the eastern Deir el-Zour province denied that Mr. Golani had been killed.
Other Nusra Front sources said they could not confirm or deny the report "because contact with al-Golani was cut," the Observatory said in a statement. The Associated Press contacted a rebel commander in a Damascus suburb, who said he believed that Mr. Golani was "alive and well" based on his contacts with other fighters, including those from Nusra Front. He declined to elaborate or be identified for security concerns.
The report comes as the fragmented rebels have suffered significant losses on the battlefield.
Syrian troops earlier Friday killed at least 40 opposition fighters, including Nusra Front members, in an ambush near Damascus, the government said. Mr. Assad's forces backed by Lebanese Hezbollah gunmen also seized control of a rebel ammunition supply route on a highway linking the capital to its eastern suburbs -- part of a blistering government offensive to bolster its position amid an international push for peace talks.
The Nusra Front has emerged as one of the most effective among rebel groups fighting Mr. Assad, and it has claimed responsibility for numerous suicide bombings against government targets.
The U.S. State Department put the group on its list of terrorist organizations for its connections to al-Qaida.
Mr. Golani, who fought previously in Iraq, is a shadowy figure who is believed to have spent time recently in rebellious suburbs south of Damascus. Rebels have also gained footholds in mountainous regions of Latakia, which is largely loyal to Assad, and he may have gone there to direct fighting.
Mr. Golani gained prominence in April when he rejected an attempted takeover of the group by Abu Bakr al-Baghdadi, head of the Islamic State of Iraq, revealing a growing rift within al-Qaida's global network. Mr. Golani at the time distanced himself from claims that the two groups had merged into a group called the Islamic State of Iraq and the Levant. Instead, he pledged allegiance directly to al-Qaida's leader Ayman al-Zawahri. He said Mr. Baghdadi's announcement of the merger was premature, and that his group will continue to use Jabhat al-Nusra as its name.
The group is more popular in Syria than the ISIL, largely made up of foreign fighters, which has been criticized for its brutality and for trying to impose a strict version of Islamic law in areas under its control. Mr. Golani's death, if true, would likely strengthen ISIL at a time of growing infighting between al-Qaida extremists and the more moderate rebels from the mainstream Free Syrian Army.
Mr. Assad's forces have been gaining ground in rebel-held areas around the capital, the seat of his power, and have made progress against outgunned and fragmented fighters in several areas.
On Friday, the state-run news agency SANA said 40 rebels died in the ambush near Otaiba.
The offensive coincided with an international push for a peace conference to be held in Geneva. Both sides want to bolster their ground position ahead of the talks, expected next month. But no final date has been set, and it is unclear whether the sides will reach accord on the agenda.