Rival drug gangs in Mexico are using the YouTube website to taunt each other with bloody slideshows and murder clips.

One popular video on the site shows a man being shot in the head.

Another shows photos of another execution victim, his missing face a mangled mess of flesh.

The violent gang war - between the Gulf Cartel from northeastern Mexico and traffickers based in the western state of Sinaloa - claimed more than 2,000 lives last year.

President Felipe Calderon has sent thousands of troops to several chaotic states to take on the drug gangs, who have decapitated police and killed soldiers.

Several slideshows are backed by the pumping bass and blaring horns of a famous "narco corrido" ballad called To My Enemies, widely seen as a musical attack on the Gulf Cartel's private army, The Zetas.

The singer Valentin Elizalde was shot dead last year after reportedly performing the song at a concert in Gulf Cartel territory.

In one YouTube post, a user offers about £2,300 to anyone who can show proof of having killed members of The Zetas, "via photo, video or presenting the body".

A spokesman for Mexico's attorney general's office said that some of the people who abuse each other on YouTube seem to have insider knowledge of the drug gangs.

"The messages give the impression that members of organised crime are participating," Jose Luis Manjarrez said.

"We can't rule out, but neither can we be totally sure, that this is being used as a form of communication by organised crime."