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 the fighting in Syria, said senior Nusra Front leaders contacted by activists in Latakia and the eastern Deir el-Zour province denied al-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. A rebel commander in a Damascus suburb said he believed al-Golani was “alive and well” based on his contacts with other fighters.