Police in Seabrook, New Hampshire, asked the public to avoid the area at a shopping plaza on Tuesday while they investigated a suspicious package.
The nature of the suspicious package at Southgate Plaza wasn't immediately clear, but police later said it was a pressure cooker.
They were working to determine whether it was left with intent to hurt others, but the condition in which it was found was not deemed to be a threat.
Officers had taped off the plaza, which houses a Market Basket, UPS Store, TJ Maxx and other stores.
Aerial footage showed an officer in a bomb-proof suit examining a shopping cart.
Seabrook's police chief said the device was suspicious and investigators want to know who left it there and why.
The incident began when someone called police to report the pressure cooker in a shopping cart in the Market Basket's parking lot, police said. Officers evacuated the supermarket and a nearby Paper Store and requested help from the state bomb squad, which found the device wasn't a threat.
Anyone with information about the case is asked to call Seabrook police at 603-474-5200.