Authorities are searching for an armed woman in connection with alleged threats that led to lockouts at nearly 20 other Colorado schools, including Columbine High School.

The FBI Denver Division and the Jefferson County Sheriff's Office identified the woman as 18 year-old Sol Pais, who, according to CNN, allegedly “made threats in the Denver metropolitan area.”

The sheriff's office said in a Facebook post that the threats were “credible but not specific” and did not target any school in particular.

"It's a credible threat… but she did not make it directly," said Jenny Fulton, a spokeswoman with the sheriff's office. "There may be some connection to Columbine but it wasn't a specific directed threat towards Columbine."

Earlier on Tuesday, the Colorado Department of Education recommended that Denver area schools conduct a "lockout" after receiving the threats.

"We will have extra safety and security staff on site at all schools affected," Jefferson County Public Schools said in a statement.

Aurora Public Schools, east of Denver, said all of its schools were "placed in secure perimeter adding that the schools “have no info about a specific threat related to any schools in APS.”

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Colorado schools have remained on high alert of a possible gun attack since April 20, 1999, when two students killed 12 students and one teacher in a mass shooting at Columbine. The two shooters took their lives in the school's library.=