BIRMINGHAM, Ala. - An undercover officer posing as a prostitute in Alabama tried more than once to run off a 13-year-old boy who asked her for sex, but police say the teen insisted and had to be arrested.

Authorities in Mobile said Wednesday the teenager has been charged with a misdemeanor count of loitering while looking for a prostitute. The next-youngest suspect nabbed in the sting was 22.

Police set up the sting in a residential area last week because of complaints about prostitutes trolling for business. Officer Christopher Levy says it's not clear exactly what the teen said to the officer, or how she responded.

The boy's name was not released because of his age and it's not clear whether he is still in custody.

Fifteen people were arrested during the sting.