The severed heads of two Mexican policemen have been found in the resort city of Acapulco at the site of a recent shootout with drug-traffickers.
Both were members of a rapid response unit of the federal Preventative Police which took part in the January shooting in which four traffickers died.
Their heads were dumped outside the city's finance department, 2km (1.2 miles) from the main tourist zone.
The bodies were later found wrapped in a sheet and rug elsewhere in Acapulco.
A sign left with the heads read: "So that you learn to respect."