YORKVILLE, Ill. (AP) — Police outside Chicago say a man walking through woods behind his home discovered a World War I-era grenade by accidentally kicking it.

The (Aurora) Beacon-News reports the man found the grenade about 9 p.m. Sunday. Yorkville Police Deputy Chief Larry Hilt says the man called police, who called the Kane County Bomb Squad as a precaution. The bomb squad took the grenade to its office and X-rayed it, which found that it did not have any active explosives in it.

Hilt says a Yorkville detective who has an interest in history identified the ordinance as a Mills Bomb.

Yorkville is about 50 miles west of downtown Chicago.