A senior commander in Iran's powerful Revolutionary Guard has been killed by Islamic State extremists on the outskirts of the Syrian city of Aleppo, Iranian state media reported.
A state television report said General Hossein Hamedani was killed in the suburbs of Aleppo while "carrying out an advisory mission". The official IRNA news agency read a statement by the Guard which blamed IS for his death.
The announcement came as IS launched a surprise attack in the northern province of Aleppo, seizing a string of villages from rebels. The Syrian Observatory for Human Rights said the advance by the extremists was the most significant in months.
It was not clear whether Gen Hamedani's killing was related to that IS offensive. It comes amid a wave of Russian air strikes and a ground offensive by the Syrian army in the country's central region.
The Observatory said IS seized the villages of Tal Qrah, Kfar Qares and at least four other small settlements in the northern Aleppo countryside. IS-affiliated accounts on Twitter also announced the militants had seized those villages.
"Brig Gen Hamedani was martyred by Daesh terrorists during an advisory mission in the suburb of Aleppo," said the statement on IRNA, using an Arabic acronym for IS.
He is one of the most senior Guard commanders to be killed in Syria, and the second this year. He was a veteran commander who had an important role in Iran's 1980-88 war with Iraq.
In January, Brig Gen Mohammad Ali Allahdadi was killed in an Israeli air strike in Syria that also killed six Lebanese Hezbollah fighters.
Iran is one of Syrian president Bashar Assad's main allies. Tehran has provided his government with military and political backing for years and has kept up its support since Syria's civil war began in 2011.
Guard commanders claim Iran only has high-level advisers in Syria, denying it has fighters there.
Assad is from the Alawites, an offshoot of Shiite Islam. Iran is majority Shiite, while Syria's rebels are mostly Sunni.
Meanwhile, Turkey's state-run news agency said Syrian journalist Salih Mahmud Leyla, who reported for the agency from northern Syria, had been killed in car bomb attack.
The Anadolu Agency said Mr Leyla, 27, died in the attack in the town of Hreitan, in northern Aleppo province. It said the attack is believed to have been carried out by IS militants.
Mr Leyla sent photographs and videos from clashes in northern Syria and also reported on hardships suffered by the people there, Anadolu said.
In July, he received injuries to his face while reporting on clashes in Aleppo and was taken to Turkey for treatment.
Activists reported more than 20 explosions in the northern city of Raqqa, held by IS.
A collective called Raqqa is Being Silently Slaughtered said 22 blasts shook the city.
The Britain-based Syrian Observatory for Human Rights said the explosions killed 14 IS fighters and wounded more than 20.
The group said it was not clear if the explosions were the result of air raids by the US-led coalition or Russian warplanes.
Activists said a training facility, known as Vanguards Camp, was hit on the southern edge of the city.
France's defence minister Jean-Yves Le Drian said French warplanes had bombed a training camp in Raqqa.