The Federal Bureau of Investigation has joined in the search for a 14-year-old girl believed to have been abducted from her home in Virginia.

Isabel Shae Hicks. Louisa County Sheriff's Office

An Amber Alert was issued for Isabel Shae Hicks, who vanished at about 1 a.m. Monday from her residence in Bumpass, around 42 miles northwest of Richmond. The Louisa County Sheriff's Office said in a Facebook post on Friday that they believe she may have been abducted by 33-year-old Bruce William Lynch, also of Bumpass.

A felony abduction warrant has been issued for Lynch and the pair may have left Virginia, the department said.

Detective Chuck Love told NBC News that Isabel was last seen by her sister in their shared bedroom. When the sister woke up later in the morning and noticed Isabel was gone, she told her parents who then contacted the police.

Lynch had "recent suicidal ideations" and may be in possession of a handgun, the sheriff's office said. He should be considered armed and dangerous. Detective Love said camping gear was reported missing from Lynch's home.

The FBI Richmond Division is assisting in the search for Isabel and said she is considered an "endangered missing juvenile." The agency said in a missing person's poster that anyone who sees the teen or Lynch should call law enforcement immediately and not approach them.

The suspect is believed to be traveling with Isabel in a silver-blue 2003 Matrix Toyota with a Virginia license plate.

Bruce William Lynch. Louisa County Sheriff's Office

"Information received appears they may be traveling out of state and staying in areas where they could camp," the sheriff's office said.

Love told NBC News that the sheriff's office has been flooded with tips from outside of Louisa County but so far Isabel and Lynch have not been spotted.

The family of Isabel joined authorities Thursday for a press conference and begged for the teen's safe return.

"We miss you very much and we want you to come home," her brother, Blake Saylor, said. "I love you forever. ... I just need my best friend back."