Bomb disposal crews cordoned off a street in Grimsby following the discovery of a suspicious device.
Enquiries were completed and it was determined that there was no risk or danger to the public.
A man was arrested after police also found a crossbow and an air rifle inside the property.
The cordon was in place from 2.30pm on Thursday, March 19 in the Wellington Avenue area of Grimsby.
The Explosive Ordnance Disposal team attended at around 5pm.
The device was seized by police in addition to a crossbow and air rifle.
Superintendent Craig Scaife said: “I want to thank the local community for their understanding and patience, in what is already a worrying time for everyone, whilst we carried out enquiries.
“The cordon has now been lifted as the incident has been brought to a safe conclusion and there is no risk or threat to the public.
“One man has been arrested and he remains in our custody being questioned by officers.”