The severed head of a town councilman was dumped outside the offices of a newspaper in Mexico's Gulf state of Tabasco in what the paper's publishers said was an attempt to intimidate reporters.

The head, left outside Tabasco Hoy's offices in Villahermosa, was wrapped in newspaper inside a cooler and left by a man who stepped out of a sport utility vehicle early Saturday, the paper said on its Web site.

Police and soldiers said the head belonged to Terencio Sastre, a councilman from the nearby municipality of El Cedro, whose body was found on the side of a road Friday.

"It has all the characteristics of an act of intimidation and an attempt to silence the freedom of information that the publishers exercise," Tabasco Hoy said in a statement.

It sent a letter to President Felipe Calderon and other officials, urging them to guarantee the staff's safety. The newspaper did not discuss who was behind the killing.

Mexican drug gangs often decapitate rivals as a means of intimidation and are blamed for killing dozens of Mexican journalists in recent years.

In January, Tabasco Hoy reporter Rodolfo Rincon disappeared and has not been seen since.

Shortly before his disappearance, Rincon wrote an article on drug gangs that identified houses where narcotics were sold.

Mexico has become the world's second-most dangerous place for journalists after Iraq with seven journalists killed across the country since October. A Mexican TV reporter and cameraman disappeared earlier this month in the northern city of Monterrey.

Many journalists hold back from reporting on drug gangs.

On Thursday, the newspaper Cambio Sonora in the northwestern city of Hermosillo announced it was shutting down temporarily after assailants tossed a hand grenade from a passing car at its offices.