Nassau police evacuated dozens of people and called in the department's bomb squad after a suspicious device was found in a Valley Stream backyard on Sunday afternoon.
The device turned out to be a commercial pyrotechnic, police said.
Officers discovered the device at a house on East Chester Street after responding to the home at about noon on an unrelated matter, police said.
The device, which looked like a long cardboard tube covered in red tape with visible fuses, was spotted in the home's backyard, police said.
About 30 to 40 people from surrounding homes were evacuated as the item was neutralized and removed in a bomb squad containment unit, police said.
It was determined that the device was "a commercial pyrotechnic," according to police. Residents were allowed back in their homes at around 5 p.m.
Detective Sgt. Kenneth J. Catalani said, "Our awareness is heightened" after events such as the recent Boston Marathon bombings, and implored residents to call police if they see something suspicious.
Police would not address why they initially responded to the home, but said the investigation regarding the device is ongoing. They said they have not yet spoken with the homeowner, and no charges have been filed.