Amid an army offensive in eastern Aleppo, a seven-year-old girl - whose tweets drew worldwide attention - has disappeared from Twitter.
With the help of her mother, a teacher, Bana Alabed regularly tweeted in English about life in the besieged city and had amassed around 100,000 followers.
As troops pushed into the city on Sunday, the account was deleted.
Her final tweet, written by her mother, said: ‘We are sure the army is capturing us now. We will see each other another day dear world. Bye. – Fatemah’.
Aleppo, Syria’s second city, has been split in two during the country’s long conflict.
Bana lived in rebel-held eastern Aleppo, which has been relentlessly bombed by the army.
The account, where tweets were posted by both Bana and her mother Fatemah, drew attention to the plight of civilians trapped in eastern Aleppo.
Bana’s account had given a human face to the everyday reality of life in Aleppo.
She tweeted about the steady stream of bombings, sent messages to politicians to end the conflict and shared photos and short videos of herself and her brothers trying to be children in a war-torn world.
After the account disappeared, social media users tweeted their concern using the hashtag #WhereIsBana
One tweet from November read: ‘Tonight we have no house, it's bombed and I got in rubble. I saw deaths and I almost died.’
Since the start of the latest military offensive, the United Nations estimates more than 31,000 people have already fled their homes, either to government or Kurdish areas or deeper into the besieged enclave.
At least 300 people have been killed since the government-led offensive on east Aleppo and about 250,000 are thought to be trapped.
Earlier this week, Stephen O’Brien, the UN’s humanitarian affairs chief, said parts of the city were at risk of becoming ‘one giant graveyard’.
He said some people inside opposition-controlled areas were so hungry they had been reduced to scavenging.
Harry Potter author JK Rowling, who has exchanged tweets with Bana and earlier sent her entire book series, retweeted posts about Bana’s missing account.
On Friday, Rowling tweeted a video of Bana saying she was on the run and feared being killed.