Put a pin in it!

A police department had to issue a dire warning to its residents — urging them against showing up to the station with unexploded World War 2 grenades, after one woman did just that.

“Earlier today, an individual brought an unexploded WW2 grenade to the Ottawa OPP Detachment for disposal,” the Ontario Provincial Police in Ottawa recently wrote on Facebook.

“The OPP would like to remind the public that if you find such items, please do not transport them to your local police station.”

The grenade in question was found by a 77-year-old area resident who was cleaning her basement.

When she brought it to the station, she was told to leave it outside, just in case.

“You don’t know what condition they’re in, whether they can still explode,” Michael Fathi of the Ontario Provincial Police told the Ottawa Citizen.

“You don’t want to take [a] chance.”

The department, which stored it while waiting for the Canadian Forces at Petawawa to take it away, went on to explain the precarious nature of transporting grenades or any military supplies, asking residents not to pick them up, but contact them instead.

“This could obviously prove extremely dangerous to the person bringing the item and others around,” it continued in the post.

“If you find an unexploded ordnance, leave it where it is and contact your local police. The police will arrange for their Explosives Disposal Unit to attend to safely discard the item.”