The mayor of a town in the Mexican border state of Tamaulipas has been shot dead

The shooting is the latest violence in the troubled state, which saw a wave of bomb attacks. Police in Tamaulipas are investigating a mass killing of 72 migrants by suspected members of a drug gang. Meanwhile, the army said it had captured the "lieutenant" of a cartel in the northern city of Monterrey. Francisco Zapata Gallegos was captured during a raid in Monterrey. He had confessed to taking part in an attack in March 2010 that caused the deaths of two students at a Monterrey university, the army said. Zapata, whose alias is "the Bald One" is thought to have been the chief figure for the Zetas cartel in Monterrey. He had reportedly spent the past few months in hiding, but a tip-off from one of his associates led the army to his door. Away from Monterrey, the state of Tamaulipas was the target of a wave of violence. Marco Antonio Leal Garcia, mayor of Hidalgo, a small town in the western part of the state, was killed in a gun attack that also wounded his four-year-old daughter. Garcia, 46, was shot dead while driving his car. Hidalgo borders Nuevo Leon state, where the mayor of another small town was found murdered on 18 August 2010. Local police allied with a drug gang are suspected to be behind that killing. Much of the violence in the region is blamed on the Zetas, a brutal group of former elite Mexican army commandos. The US government describes the gang as the most dangerous organized crime syndicate in Mexico. Four devices exploded separately in Tamaulipas injuring at least 17 people. The explosions appeared to target places connected with the probe into the migrant killings. Police are still searching for a prosecutor involved in the case who has been missing for several days. Mexican prosecutors have said they are deeply concerned for the safety of Roberto Suarez, who is leading the investigation into the deaths. It appears that gangsters are trying to stop those trying seeking evidence of the murders. Recently, two bombs exploded in the state capital, Ciudad Victoria, targeting a television station and the offices of the transport authorities.