Isil admits its chief strategist has been assassinated in bomb attack by US forces
Terrorist group Isil has admitted its chief strategist, who laid out the blueprint for the group's attacks against the West, was killed overseeing operations in northern Syria.
Abu Muhammed al-Adnani was "martyred while surveying the operations to repel the military campaigns in Aleppo," according to the Isil-run Aamaq news agency.
The Pentagon said an air strike had targeted Adnani in the town of al Bab.
A later statement issued by the group in Aleppo province vowed to avenge his death.
Al-Adnani, whose real name was Taha Sobhi Falaha, persistently called for attacks against the West.
These resulted in 130 people killed and hundreds more injured in the November 13 coordinated attacks in Paris that hit a concert hall, a stadium and restaurants and bars.
He was a Syrian who was born in the northern province of Idlib and is believed to have been in his late 30s.
He crossed the border and joined al-Qai'da in Iraq, a precursor to Isil, after the 2003 US-led invasion.
He formally declared the establishment of a caliphate, or Islamic state, in late June 2014.
This stretched across parts of Syria and Iraq, under the leadership of Abu Bakr al-Baghdadi, and al-Adnani demanded allegiance from Muslims worldwide.
The powerful orator became the voice of Isil.
He delivered fiery sermons urging followers to kill civilians in nations supporting the US-led coalition against the group in audio files released online.
He also called for massive attacks during Ramadan earlier this year.
This call resulted in the bloodiest Muslim holy month in recent memory.
Followers of Isil carried out attacks on several continents, including the Orlando shooting, the Nice truck attack in France and a massive suicide bombing in downtown Baghdad.
Aleppo is a current focal point of the civil war in Syria, where Isil, Syrian Kurdish forces, Turkey-backed rebels and president Bashar Assad's forces are vying for control.
The province is frequently struck by both US-led coalition air strikes and Russian air raids.
Isil has suffered a string of defeats in recent weeks, including in Aleppo province, where Turkish troops and allied Syrian rebels drove the group out of the border town of Jarablus last week.
The group has lost its strongholds in Fallujah and Ramadi, in the western Anbar province of Iraq.
It still controls Mosul, but Iraqi forces are gearing up for a long-awaited operation to retake the country's second largest city.
It has also lost some of its most senior commanders and founding members over the past year.
These included its "minister of war" Omar al-Shishani, feared Iraqi militant Shaker Wuhayeb, also known as Abu Wahib, and a top finance official known by several names, including Abu Ali Al-Anbari.