Mexican Hitmen Offer Services Online

Between listings offering gas fitters and modelling agencies, a post reads: "Gun for Hire - $6,000. Professional. International. Discretion guaranteed".

Another reads: "former soldier with 10 years experience in the private sector, very professional and discreet".

A hitman called Jorge leads with: "Problems with someone? Would you like a solution? Write to me. 100% professional – we do not charge an advance".

As drug cartels and organised crime gangs step up their tit-for-tat murders by leaving bodies and severed heads in Mexico City streets, police are taking these ads seriously.