Missing Justin and Stephanie Shults: Mom flies to Belgium

The mother of an American accountant missing since the Brussels bombings was flying to Belgium on Thursday after the family said it had been wrongly informed that he had been found.

Justin Shults and his wife Stephanie have not been seen since two blasts rocked the check-in hall at the city's airport, killing at least 11 people Tuesday morning.

The explosions were met just over an hour later with another blast at a metro station in the city. At least 31 people died and more than 270 were wounded between the two sites across the Belgian capital.

PHOTOS: Missing U.S. couple Justin and Stephanie Shults

Justin, 30, is originally from Gatlinburg, Tennessee, while 29-year-old Stephanie is from Lexington, Kentucky. They both work as accountants and moved to Brussels in 2014.

They were waving goodbye to Stephanie's mother, Carolyn Moore, who was walking toward the security check-in when the blasts occurred.

Moore survived the explosions without serious injury. But the family does not know whether the couple was still in the building at the time.

This torment was compounded Wednesday after Justin's brother, Levi Sutton, told NBC News that his family had been told his brother and Stephanie were found.

Related: Brussels Terror Attacks Expose Security Challenges of 'Soft Targets'

"We do not know the severity of their injuries or what hospital they're at," he also posted on Twitter.

That hope was dashed later Wednesday when Sutton posted again that "misinformation ... was given to my family."

It was not immediately clear how the confusion arose. Sutton told NBC News that his mother, Sheila Shell, who lives in Tampa, Florida, had received a call from the State Department confirming the news.

In a statement issued through the office of Tennessee Sen. Bob Corker, the couple's families later said that "neither Belgium nor U.S. officials have confirmed that Justin and Stephanie Shults have been located."

The State Department added that "a number of U.S. citizens remain missing and not every U.S. government employee or family member on the ground has been accounted for."

See photos from the scene of the explosions in Brussels:

Justin' brother voiced his exasperation on Twitter.

"This is exactly what we were trying to avoid and now I've told friends and family members things that weren't true," he said in a message on Twitter. "Obviously we just want Justin and Stephanie to come home."

His mother was scheduled to arrive in Belgium on Thursday "and hopefully she can get some answers as things still seem to be uncertain right now," he said.

Stephanie's mother had her hearing damaged by the blast but has vowed to remain in Belgium until her daughter and son-in-law were found, her sister Betty Newsom told NBC station WAVE.