A teenager from northern England is believed to have become Britain's youngest suicide bomber after falling victim to what was described as "deliberate and calculated grooming" by Islamic State militants.
Talha Asmal, 17, reportedly blew himself up inside a car laden with explosives in Iraq on Saturday after traveling to Syria to join the militants.
The schoolboy's death has not yet been confirmed by officials, but images of him were circulated on Islamic State social media accounts.
Family members said the photos appeared to show Talha. They said in a statement that they were "devastated" and "heartbroken."
They also lashed out at Islamic State for preying on their son, saying the militants were "too cowardly to do their own dirty work."
"He never harboured any ill will against anybody, nor did he ever exhibit any violent, extreme or radical views of any kind," the family statement said.
"Talha's tender years and naivety were, it seems however, exploited by persons unknown, who, hiding behind the anonymity of the worldwide web, targeted and befriended Talha and engaged in a process of deliberate and calculated grooming of him."
On Monday, Prime Minister David Cameron said he was "deeply concerned" at the news.
Talha, from the town of Dewsbury in Yorkshire, entered Syria in April after leaving his family home with friend Hassan Munchi, 17, and boarding a flight to Turkey.
The Munchi family was already known to authorities: Hassan's older brother, Hammaad, was arrested by counter-terrorism police in 2006 when he was just 15.
He was later found guilty of taking part in a plot to kill non-Muslims.
At the time of their disappearance, the families of the two boys issued passionate appeals for their safe return, describing them as "two ordinary Yorkshire lads."
News of Talha's death first surfaced on Islamic State social media accounts, which called him Abu Yusuf al-Britani, the jihadi name he had adopted.
He was shown standing beside a black Toyota SUV apparently laden with explosives, smiling and pointing his right index finger towards the sky.
Talha is believed to be one of four people who carried out coordinated car bomb attacks near an oil refinery south of Baiji in Iraq that killed at least 11 people.
The other members of the group were from Germany, the Palestinian territories and Kuwait, the Islamic State claimed.
Around 700 Britons are believed to have traveled to Iraq and Syria to join the militant group. About half that number are thought to have returned home and roughly 30 have died in fighting.
If Talha's death is confirmed, he will be the sixth British national to have died as a suicide bomber.
The youngest until now was Hasib Hussain, 18, one of four men to blow themselves up on the London transport network on July 7, 2005.