Residents of Riverhead are being asked to remain vigilant as its town supervisor says the area is on the verge of becoming a COVID-19 cluster zone.

Currently, the town is seeing a surge of COVID-19 cases, leading to long lines at some testing sites in the area. According to county data, Riverhead has seen a positivity rate of 4% for nearly two weeks and currently has over 1,000 COVID-19 cases.

If the area remains at 4% or rises to 5% or higher in the coming days, it will become a red zone micro-cluster. That means nonessential businesses will close, schools will halt in-person learning, houses of worship would operate at 25% capacity and mass gatherings will be prohibited.

Suffolk will start a voluntary rapid testing program at Riverhead schools beginning Friday and is looking into adding a pop-up testing site. County Executive Steve Bellone blamed the increase in cases on small gatherings and Halloween parties.

Riverhead Town Supervisor Yvette Aguiar is encouraging all residents to wear masks, wash their hands and stay socially distant.

"We are aggressively approaching this, we don't want to add to that cluster," says Aguiar. "And I know the concerns of the county executive ... there is a possibility of an outdoor testing site opening within the next few days. So these are all proactive measures that we are taking."

The county says a small cluster started from a Riverhead Friendly's Restaurant when six employees became infected earlier this month.