Mexico City, Jul 12 (AP) Armed assailants killed three police officers in a region of eastern Mexico plagued by thefts of fuel from oil pipelines, authorities said.

Police in the municipality of Tezonapa in Veracruz state said the local officers were hit by gunfire while riding in a patrol vehicle yesterday. They were in an area where three days earlier authorities mounted an operation targeting "huachicoleros," or thieves who steal fuel by drilling into pipelines run by state oil company Pemex.

Local authorities say the latest Pemex report indicates there are 551 clandestine fuel theft perforations detected in Veracruz, 70 percent of them in the Tezonapa region.

In Mexico's southern state of Guerrero, four people were killed when gunmen fired on their vehicle on a rural road in the township of Coyuca de Benitez, state security spokesman Roberto Alvarez said yesterday.

Alvarez said three victims, including a 17-year-old boy, died at the scene and an 11-year-old boy died later at a hospital Tuesday night. The victims were from the community of Tepetixtla.

In the northern border city of Nuevo Laredo in Tamaulipas state, gunmen believed to be members of an organised crime group attacked a team of investigators and experts from the federal prosecutor's office looking into forced disappearances.

Prosecutor Abel Galvan told Radio Formula yesterday that the attack two days earlier was aimed at three investigative police officers and seven experts from the Attorney General's Office.

In May, the United Nations High Commissioner for Human Rights called on Mexico to take urgent measures to stop a wave of forced disappearances in Nuevo Laredo and surrounding areas.

The UN office documented the disappearance of 23 people there since the start of February, likely at the hands of security forces. Human rights groups put the number of disappeared much higher.

Videos aired by local media of the Monday attack showed an intense gunbattle that spread panic among the population. Military personnel guarding the agents repelled the attack.

Tamaulipas state security spokesman Luis Alberto Rodríguez said four people were wounded and one killed in the shootout. All were civilians except for one of the injured, who was a soldier. (AP)

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