ALPINE, Texas -- The search for a missing Sul Ross State University student with deep ties to North Texas continued on Monday, with family and friends hopeful 21-year-old Zuzu Verk will be found soon.

The Verk family lives in Keller. Zuzu attended Timber Creek High School.

According to the Alpine Police Department, she has now been missing for six days. They say she may be in danger.

Over the weekend, more than 100 people thoroughly searched the small town in southwest Texas.

Police told the local ABC affiliate, KMOI-TV, that there were no substantial leads in her disappearance. They have not elaborated on the circumstances surrounding her disappearance early Wednesday morning, or why, specifically, they think she might be in trouble.

A missing person poster for Zuzu Verk.

Her family are in Alpine helping coordinate search efforts. Her brother said on Monday they were meeting with police.

On Wednesday, police search Verk’s boyfriend’s residence.

They say he is a “person of interest” in the case, and that there are additional persons of interest.

“The residence of the boyfriend was Zuzu’s last actual known location,” said Capt. Darrell Losoya.

Police are also asking anyone with information about seeing a grey 2006 Jeep Liberty and a 2004 Mazda Miata convertible with a beige top early on Wednesday to contact them at (432) 837-3486. A $30,000 reward is also being offered for information that leads to Verk.

The local sheriff's office has also posted to Facebook asking the area's ranchers and landowners to search their properties for anything suspicious.