Police in Mexico City are investigating online classified ads posted by people selling their services as assassins for as little as $6,000.

Between listings offering gas fitters and modeling 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 organized 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.

At least 1,700 people have been killed this year in the battle between warring cartels and the raids by soldiers and federal police sent out to stop them.

Police spokesman Miguel Amelio Gomez said the problem of hitmen was real and was one they were "facing all over the country — people offer their services to kill someone for a price."

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