MEXICO CITY (AP) -- Banners have appeared in northern Mexico signed by the Zetas drug cartel saying the gang was not responsible for killing 49 people whose mutilated bodies were found on a highway in a neighbouring state. An employee of the prosecutors' office in northern San Luis Potosi state says the banners were hung from overpasses in the city of Ciudad Valles. The banners were found early Tuesday. The employee was not authorized to speak on the record, and did not give the precise wording of the banners. The bodies were found Sunday in the neighbouring state of Nuevo Leon with their heads, hands and feet hacked off. A slogan scrawled on a stone arch nearby read "100 per cent Zetas," but it may have been there well before the bodies were dumped.