Yea, I'm nearly sure thats a anti-riot water cannon. Some of our police departments bought water cannons based on Renault Kerax chassis http://www.motofakty.pl/artykul/_8222tajfun_2_8221.html as a replacement for old Jelcz Hydromil II http://imcdb.org/vehicles_make-Jelcz_model-P-420+Hydromil+II.html