Part of Bolton town centre had to be cordoned off, after a suspicious package was found in a back street.
A woman found a box with three mobile phone numbers on it, instructing someone to open or call them, in Back Spring Gardens at 0750 BST.
She alerted police who evacuated nearby Elizabeth House and erected a 100-metre (328ft) cordon.
Bomb disposal experts were called and carried out a controlled explosion. Police said they suspect it was a hoax.
The area around the package remains sealed off but the cordon has been lifted, a spokesman added.