A Fairfax County teenager who associates with gang members and has been missing since February may now be in danger, police say.

Angelica Flores, 16, of the Alexandria section of the county, was reported missing on Feb. 17 and was last seen in Fairfax City, Fairfax County police said. Unspecified information developed on Monday led detectives to believe Flores may be in danger.

Flores is described as 4 feet 11 inches tall, about 110 pounds and has brown eyes and black hair. Her hair might be dyed red. Officials said Flores is in the 10th grade at Mount Vernon High School in Alexandria.

Police declined to name the gang Flores had ties to Tuesday, but in a court document filed in February she is listed as an associate of MS-13.

The violent street gang has been behind the disappearance and killing of a handful of teenagers in the D.C. area in recent years. In August, Miguel Angel Ruiz Carillo, 18, of Mount Vernon, disappeared, and his body was discovered later that month in Prince William County. MS-13 associates have been charged in his killing.

In January, Damaris Reyes Rivas, 15, of Gaithersburg, was killed in the Springfield area in retaliation for the MS-13-related killing of a man in Prince William County about a week earlier. Ten associates of the gang were charged in that slaying.

In late 2016, authorities wrote in search warrants that MS-13 was behind the killings of Sergio Triminio, 14, of Alexandria, and Edvin Mendez, 17, of Falls Church, whose bodies were discovered in Fairfax County’s Holmes Run Park in March 2017. No charges have been filed in that case.