HICKSVILLE - "MS 13" gang tags were left on a fence and four cars in Hicksville Friday night.
Residents along Violet Avenue say they woke up to find "MS 13" scrawled in spray paint on their property.
Nassau police say they have increased patrols in the area.
A neighbor on Violet Avenue gave News 12 Long Island a surveillance video from around the time of the incident. It shows three people quickly riding by on bicycles. Police are also reviewing the video.
Authorities say the county's gang unit is investigating the incident in an effort to determine if it was a prank or actual gang activity.
The graffiti incident follows what police believe to be the gang-related killings of two teen girls in Brentwood last week.