|Mexican authorities are struggling to contain a wave of brutal killings by drug cartels [Reuters]
Suspected drug traffickers have killed the mayor of a small town in northern Mexico, in a region where two car bombs exploded last week and the bodies of 72 murdered migrant workers were found.
Marco Antonio Leal was shot dead by armed men in vehicles on Sunday as he drove through his rural municipality of Hidalgo in Tamaulipas state, the local attorney-general's office said.
Leal's four-year-old daughter was wounded in the attack.
It was not immediately clear why Leal was targeted, but Tamaulipas has become one of Mexico's bloodiest drug flashpoints since the start of the year as rival traffickers from the Gulf cartel and its former armed wing, the Zetas, fight over smuggling routes into the US.
Leal had taken office in 2008 and was supposed to step down in December.
Former army commandos
Hidalgo, a town of 25,000 people, is located 90km northwest of the state capital, Ciudad Victoria.
It is also near the border with Nuevo Leon state, where the mayor of another town, Santiago, was found murdered on August 18. Local police allied with a drug gang are suspected in that killing.
Much of the violence in the area is blamed on the Zetas, a brutal, well-trained group of former elite Mexican army commandos that the US government calls the most dangerous organised crime syndicate in Mexico.
Attacks were also reported in the coastal city of Tampico late on Saturday, where two people were wounded when a police station was bombed.
Hours earlier, two bombs exploded near a morgue in Reynosa, on the US border, where the bodies of the Central and South American migrants - 58 men and 14 women - killed last week, were being kept.
Fifteen people were injured in the blast, local media reported.
Al Jazeera's Mariana Sanchez, reporting from Mexico City on Monday, said: "There has been a sort of turning point in the last week where we have seen a massacre of 72 migrants, two car bombs in the capital - one against a television station and another against a police station - and three grenade attacks.
"There is a difference in the tactics because we are seeing more attacks against the population. So it seems like the drug gangs are trying to put fear into the population. They don't want any investigation and they don't want the press to report either."
Mexican government officials have said drug gangs are increasingly extorting and kidnapping migrants to raise money because a controversial government clampdown on organised crime has eaten into their other sources of revenues.
Turf wars between Mexico's seven major drug cartels and government forces have killed at least 28,000 people since Felipe Calderon, the Mexican president, deployed tens of thousands of soldiers to crack down on the illegal trade in December 2006.