@kus-knee,
"කුණු දැම්මොත් ගුටි" or "කුණු දැමීම බල්ලන්ට පමණි"
I see these signs around lots of places in my country.
කුණු දැම්මොත් ගුටි - If you needs to get punch, you can put your wastes here
කුණු දැමීම බල්ලන්ට පමණි - Only dogs could put wastes here

But I think the country got lots of dogs than men lol :D

Cheers~