If you see an old tennis ball in a park police are warning you to not touch the ball.

Police in Kent, Washington say that people are using tennis balls to make tennis ball bombs and are leaving the balls behind in parks.

If you see a worn tennis ball that appears to be burnt or has a wick attached to it there could be fireworks or other explosives in the ball.

More often than not those using the balls for explosives do not mean to harm others, but they are left behind when the explosives do not go off. Thus, if you touch the ball while it may be smoldering it could set off the explosives. 

There have been cases reported in the past where dogs have retrieved balls in parks that have fireworks in it and when the dog bites down on the ball the explosives go off.

And while this warning may have been issued in the state of Washington, officials say everyone in the country should heed the warning.

Police say if you see anything suspicious in parks you should always call them first and allow their team(s) to investigate the matter.

This is good to know as summer approaches and many will soon be frequenting parks in the area.