Missing Texas teen believed to be in 'imminent danger'

A massive search effort is underway for a young woman who mysteriously vanished outside her Texas home on Christmas Eve, with law enforcement officials saying she could be in "imminent danger".

Camila Mendoza Olmos, 19, was last seen leaving her home in Bexar County, Texas the morning of 24 December, according to the Bexar County Sheriff's office.

She normally goes on a morning walk, but her mother became concerned when she did not come home at a reasonable time, the sheriff's office said.

Sheriff Javier Salazar told ABC News that authorities believe she is in danger and are not ruling out kidnapping or trafficking. They are also considering that the case may cross international borders.

But, he added, Mendoza Olmos may have left on her own accord.

The search, now going on for nearly a week, has turned up scant clues, primarily a video believed to be of her recorded the day she disappeared. Surveillance footage shows a woman searching in the back of her car for an unknown item, the sheriff's office said.

Authorities believe she then walked somewhere, because her car was left behind.

The only items she had on her, authorities said, were her car keys and possibly her driver's license. They were concerned that she left her phone behind, which was unusual.

Sheriff Salazar also told ABC News that Mendoza Olmos, who is a US citizen, was not detained by Immigration and Customs Enforcement (ICE), which has been conducting sweeps of suspected illegal immigrants throughout the country.

"That was a personal concern. So, I had it checked to make sure that there were no stops, no detentions, and that she's not somewhere in a federal detention facility," Salazar told the outlet.

Authorities have deployed deputies, investigators, search-and-rescue resources and teams, drones, and cadaver dogs in the search for Olmos, the sheriff's office said.

FBI officers have also been helping out local law enforcement, Sheriff Javier Salazar told CBS.

"Cami needs us," her aunt, Nancy Olmos, wrote on social media. "By the grace of Jesus Christ, we will find you, Cami."