What has happened?
Isis (Islamic State) reported the death of its chief spokesman, Abu Muhammad al-Adnani, today, potentially signalling the loss of a senior militant who has steered the group's campaign to bring violent operations to the West.
Does it hurt Isis?
If confirmed, Adnani's death would damage Isis in two areas that have made the terror organisation particularly dangerous: its sophisticated use of social media to reach a global audience, and its willingness to employ the crudest forms of violence in scattered plots outside Iraq and Syria.
It would be a significant blow at a time when the group is already fending off attacks from Western-backed forces on the ground and a two-year air campaign that has deprived it of territory and resources.
How did he die?
In a tweet, Amaq news agency, Isis' media arm, said that Adnani had been killed while inspecting troops in Aleppo. It did not say exactly when, where or how Adnani died.
What is Isis saying about his death?
In a longer statement posted on Telegram, Amaq boasted of the group's resilience despite Adnani's death. "The blood of the sheikhs will only make it more firm on the path of jihad and determination to take revenge and assault," Amaq said, according to a statement from Site Intelligence group.
Can we be sure he's dead?
Adnani's death has been rumoured several times before. US officials could not immediately confirm the report of Adnani's death, but a senior defence official said that aircraft belonging to the US-led coalition had targeted a "senior leader" from Isis in al-Bab, a city in northern Aleppo province, today. It was not clear whether that leader was Adnani.
"We are still assessing the results of the operation at this time," the official said.
Where is the conflict at?
While US war planes continue their long air war over Syria, recent strikes have been focused in areas in eastern and far northern Syria, where allied Syrian forces are battling the militants and where American aircraft are less likely to overlap with Russian and Syrian warplanes, which are also conducting strikes across Syria. In recent weeks, Russian and Syrian planes have intensified their activities over Aleppo, gripped by intense fighting as government-backed forces and rebels battle for control of the city.
Who was Adnani?
A Syrian national born Taha Sobhi Falaha, Adnani was among a core group of Isis operatives who could claim direct ties to Abu Musab al-Zarqawi, the Jordanian extremist who launched the organisation then known as al-Qaeda in Iraq after the US invasion of 2003.
"He was their most prolific and public spokesman," said Will McCants, a former State Department official and expert on Isis. "The war of words between al-Qaeda and Isis, the justification for war on the west - that was all Adnani's doing."
Like Abu Bakr al-Baghdadi, the leader of Isis, Adnani is believed to have been held in US military custody in Iraq roughly a decade ago, only to be released and help the organisation survive near-extinction to re-emerge later as Isis.
What was his importance to al-Qaeda and Isis?
Because of his Syrian nationality, al-Qaeda relied on Adnani to help the organisation establish a foothold in Syria as the country fell into civil war. But Adnani later helped orchestrate the Iraq-base affiliate's split from al-Qaeda, a rupture that led to the formation of Isis and its rapid emergence as a terror group with more followers and violent capacity than its parent organisation had amassed in years.
In statements announcing Adnani's death, Isis described him as a descendant of the tribe and family of the Prophet Muhammad, a clue that Adnani was possibly being groomed as a replacement for Baghdadi if the Isis leader were to be killed, McCants said.
What was Adnani known for?
In a steady stream of audio messages, Adnani both set and articulated the organisation's violent agenda, repeatedly emphasising the priority of targeting the West. Earlier this year, during the Islamic holy month of Ramadan, a recording attributed to Adnani called for a "month of conquest and jihad. Get prepared, be ready. . .to make it a month of calamity everywhere for the non-believers. . .especially for the fighters and supporters of the caliphate in Europe and America".
Adnani was a principal architect of a vast propaganda apparatus that produced thousands of videos - ranging from gruesome recordings of beheadings to the tourism bureau-style depictions of bustling markets - that helped draw thousands of foreign fighters to Isis' ranks in Iraq and Syria.
Because of his influential role in promoting the group's vision, Adnani was a target for US and allied military operations. He is believed to have been targeted in an American air strike last year but survived.
What about his role in terror attacks?
Adnani was also responsible for essentially rescinding the call for foreign recruits as Isis began to lose territory in Syria and Iraq amid a barrage of US and allied airstrikes.
"If you can kill a disbelieving American or European - especially the spiteful and filthy French," Adnani said in 2014, "Kill him in any manner or way however it may be."
While little is known about the structure and organisation of Isis' cell responsible for plotting external attacks, US officials and counter-terrorism experts believed that Adnani played an important role in identifying recruits from Europe and elsewhere who could be groomed and sent back to carry out attacks.
What impact will there be on the battlefield?
If Adnani has been killed, it was not immediately clear what operational impact his death might have on Isis. The US military claims to have killed 45,000 militants, including a number of senior leaders, in air and long-range rocket attacks since its campaign began in 2014. But the group continues to control two of Iraq and Syria's largest cities and have vowed to resort to guerrilla attacks.