Cops are looking for a man wanted for the sexual assault of a child on the Lower East Side.

The unidentified white man, in his 40s, allegedly accosted the victim in a branch of the New York Public Library on East Broadway and Jefferson Street at about 5 p.m. last Thursday.

He grabbed her by the shirt, covered her mouth, fondled her and fled, police said.

The thug is about 6-feet tall with a medium build and short salt-and-pepper hair. He was dressed in a black T-shirt, shorts and a gray cap and was carrying a black bag with a strap.

Anyone with information in regards to this incident is asked to call Crime Stoppers at (800) 577-TIPS.