LONDON — Bana al-Abed and her mother, Fatemah, whose plight in Aleppo has captured the world’s attention through Twitter, have appealed to First Lady Michelle Obama in a video message sent to NBC News.

“I talk to you as a mother,” Fatemah says in the message. “I implore you to help us ... because we are so afraid.”

The message ends with a plea from seven-year-old Bana: "Hello, Mrs. Obama. Please help us.”

The girl and her mom have become known around the world after posting regular updates on the war raging around them.

However, Syria’s President Bashar Assad has called the Twitter account propaganda promoted by terrorists or their supporters.

Speaking with NBC News via Skype late Thursday, Fatemah confirmed that she and Bana remain in the shrinking rebel-held pocket of devastated eastern Aleppo.

The evacuation of civilians to the relative safety of opposition areas in Idlib and the Aleppo countryside began Tuesday.

More were waiting Friday to be taken out of eastern Aleppo by bus, but World Health Organization officials said evacuations had been aborted. Rebel sources told Reuters that the operation stalled after pro-government militias opened fire on buses carrying civilians. A Syrian official told the news agency that the rebels had tried to smuggle out captives who they had abducted during the conflict, as well as weapons, something the rebels denied.

Related: Bana al-Abed Shares Daily Battle to Stay Alive

Posts on Bana’s Twitter account Friday morning said the cease-fire between rebels and Syrian forces had been broken.

“Civilians are in danger. I beg [the] world ... [you] do something now to get us out,” it read.

Share this message to whole world. #Aleppo ceasefire broke, civilians are in danger. I beg world u do something now to get us out. - Fatemah — Bana Alabed (@AlabedBana) December 16, 2016

“Please save us now,” another said.

Please save us now. - Bana #Aleppo — Bana Alabed (@AlabedBana) December 16, 2016

Speaking overnight, Fatemah told NBCNews she was fearful of being targeted by victorious Syrian regime forces and was likely to leave.

Related: Behind the Grim Numbers — How These 9 Kids Died in Aleppo

Fatemah said: “I think I will go out. I don't know where and how and what is the guarantee that I can have to go safely with my children and my family,” Fatemah said. "I’m afraid.”

Reflecting on her tweets from Aleppo, which have attracted more than 300,000 new followers, Fatemah said she had no regrets.

“I am grateful and that I made .. we made, me and Bana, [this Twitter account]. This is our duty because this [is] our country, because this [is] our children," she said.

“I feel that I am a mother of all the children here in Aleppo, not for my kids. So, I must be strong and have this courage to talk to all the world about what happening in here in Aleppo.”