The message from a family that has become a symbol of Syria's suffering was heartbreaking.

"We are sure the army is capturing us now. We will see each other another day dear world. Bye. — Fatemah."

Shortly after the post, the Twitter account disappeared.

The last tweet posted to the account of Fatemah Al-Abed and her 7-year-old daughter, Bana. Twitter

Fatemah's dispatches from inside Eastern Aleppo have shocked and captivated readers around the world since she began tweeting from the account on behalf of her 7-year-old daughter, Bana, in September.

The family has been documenting their struggle to survive in besieged Eastern Aleppo as the Syrian army continues to gain ground against rebels, calling on world leaders to stop the violence and rescue Syrian children as recently as Sunday morning.

But by late afternoon, the account had gone dark.

Related: 'We Give Up on Life': Syrian Family Tweets More Despair from Aleppo

Searches for the Twitter handle returned an error saying "the page doesn't exist." Twitter policy says an account will be suspended only if users are inactive, leading some on social media to speculate that the family's hideout had been discovered and that the Syrian army had deleted the account.

Last week, she posted that she was worried that the army would target her and her family because of the posts.

Social media quickly erupted with calls to find the Bana on Sunday, and the hashtag #whereisBana began trending. Author J.K. Rowling retweeted several photos of Bana with the hashtag. Rowling began communicating with the family online after Fatemah tweeted Rowling to ask for a copy of the first Harry Potter book.

Related: 'Bye': Terrified Family Tweeting from Inside Aleppo Says Farewell

Friday, Rowling shared a video of the little girl asking for help.

"Hello my friends how are you," Bana asks in halting English. "I am on the run and now I am feared being killed. Please save us. Thank you!"

Bana had just begun reading the Harry Potter series with her siblings when her home was destroyed in a bombing. Her mother shared a photo of a stunned and dust-covered Bana shortly afterward.

Since then, the family has been on the run.

The United Nations estimates that more than 31,000 people from East Aleppo have been displaced in the last week.