Laborers found beheaded on ranch

Drug traffickers launched grenade attacks on soldiers Monday at a ranch in Guatemala's remote northern Petén department, where authorities made the gruesome discovery of a brutal massacre of 27 laborers in an incident that has sparked anger across the Central American nation.

A group of armed men in a pick-up truck attacked law enforcement authorities, killing one of the police officers who were at the scene investigating this weekend's mass killing. All of the victims' bodies, apart from one, were found beheaded at the Los Cocos ranch. Its owner, Otto Salguero, is suspected of having ties to traffickers.

President Álvaro Colom declared a state of siege in Petén for 30 days and called for calm.

Interior Minister Carlos Menocal, who blamed the massacre on the Mexican Zetas cartel, said that about 40 men with assault rifles invaded the ranch on Sunday looking for Salguero. They slaughtered the farm workers one by one when they failed to tell the men where the owner was. Two people escaped and were able to tell authorities what had happened.

Some of the victims' legs and arms were amputated while their blood was used to write threatening messages on the walls of the main house, Menocal said. One of the messages read: "Salguero beware, I am going to leave you the same way. Zetas 200."

The incident marks Guatemala's worst massacre since the country's Civil War, which officially ended in 1995.

Late Monday, military forces said that they killed two Zeta suspects and captured another, but couldn't immediately say if they were members of the so-called Zetas 200.

Petén is Guatemala's largest department, and is mostly made up of jungle. It shares a long border with Mexico. Authorities have a difficult time patrolling the area, which is controlled by traffickers.

After Monday's shootout, residents said they were afraid to leave their homes.

President Colom said that security forces have retaken control of the department and its access roads.

Referring to the killings, the president called them a "grim and savage" act, adding that all the victims were unarmed day laborers.

At the morgue of the town of La Libertad, relatives of victims have so far identified the bodies of 14 workers, including three women and two teenagers aged 13 and 16.

Police and elite army troops have cordoned off the area as they search for those responsible. During Monday's gun battle, traffickers also fired machine guns at a school, which forced classes to be cancelled in some municipalities. There was another grenade attack on a house, but no casualties were reported.

According to authorities, security forces stopped a car carrying alleged gunmen in a neighborhood of Flores, the capital of Petén.

Menocal, who has traveled to Petén, said it was only a matter of time before all of the murderers are captured.

Guatemala already has one of the highest murder rates in Latin America with a daily average of 18 killings. Most crimes are attributed to feared drug gangs.