A top commander of the Islamic State extremist militia group, who was known as Abu Umar al-Shishani, is dead after suffering serious injuries in an airstrike in northeastern Syria ten days ago.
"He was pronounced clinically dead three days ago. Today I can confirm he is dead," Rami Abdel Rahman, head of the Britain-based Syrian Observatory for Human Rights, told dpa.
The Pentagon announced last week that it had targeted al-Shishani and US media reported he was assumed to be severely injured. US officials have dubbed him Islamic State's "minister of war."
Prior to the Pentagon's announcement last week, there had been false reports of his death, which is common when dealing with airstrikes on underground groups.
Al-Shishani, whose real name is Tarkhan Tayumurazovich Batirashvili, was a former sergeant in the Georgian army and his unit of the army allegedly received training from US forces.
In 2012, he left Georgia after being imprisoned and embracing hardline Islam, and later turned up in Syria. In 2013, he helped to spearhead an extremist group's attack on the Syrian government's Menagh military airbase in Aleppo province.
His distinctive red hair and military background made him a popular icon in jihadist circles and he eventually led a group of foreign fighters who joined Islamic State.
The air raid, which struck al-Shishani's convoy south of Syria's al-Hassakeh province, injured him seriously and killed 11 of his bodyguards, according to Abdel Rahman.
In 2014, Batirashvili was designated as a global terrorist under US Treasury sanctions.