MEXICO CITY (AP) — Two severed heads were dumped on a street corner near Mexico City's historic colonial core early Wednesday, a rare instance in the capital of the kind of grisly killings and public displays of murder victims more commonly seen in other parts of the country.

A statement from the city prosecutor's office reported that a man left the heads in two black bags in the morning at an intersection about eight blocks from the city's Zocalo, or main square, and about four blocks from the notoriously gritty neighborhood of Tepito.

Prosecutors said later that relatives had identified one of the victims as a 19-year-old from the Gustavo A. Madero borough. They were working to determine when and where the victims died. There was no immediate word of any arrest.

In areas of Mexico that are drug cartel strongholds, gangs have often murdered and mutilated victims and then left the remains in public as a warning to foes or people who defy them. Such displays have been rare in the capital, however, which has often been said to be a relative oasis from the worst of the country's cartel violence.

But those perceptions have been changing recently as drug gang influence increasingly appears to be felt in Mexico City. In July, road blockades and a sustained gunbattle between gang members and about 1,300 heavily armed marines and police left eight dead in Tlahuac, a poor neighborhood on the city's southern outskirts.