Ten suspected criminals were killed in shootouts in Nuevo Laredo, a border city in northern Mexico, a city spokeswoman told Efe.

Soldiers, marines, state police and municipal police engaged armed subjects in gunfights early Saturday that lasted several hours, the Nuevo Laredo spokeswoman said.

The shootouts started around 2:30 a.m. Saturday at kilometer 10 of the highway that leads from Nuevo Laredo, located across the Rio Grande from Laredo, Texas, to the airport.

Army troops encountered a convoy of gunmen on the airport road and came under fire.

The soldiers engaged the gunmen, setting off a chase, the city spokeswoman said.

Marines, meanwhile, spotted another group of gunmen in Nuevo Laredo, which is in Tamaulipas state, and engaged them in a firefight, killing 10 of the suspects.

The army is carrying out "Operation Northeast" in the states of Nuevo Leon, Tamaulipas, Coahuila and San Luis Potosi against the drug cartels that operate in the region.

More than 50,000 people, according to official figures, have died in drug-related violence in Mexico since late 2006, when President Felipe Calderon took office and declared war on the country's powerful drug cartels.

Calderon has deployed tens of thousands of soldiers and Federal Police officers across the country to combat drug cartels and other criminal organizations.

The use of the armed forces to fight drug traffickers, however, has failed to stop the violence.

Mexico registered 27,199 murders in 2011, or 24 per 100,000 people, the highest number since Calderon took office, the National Institute of Statistics and Geography, or INEGI, said in a report released on Aug. 20.

The Movement for Peace with Justice and Dignity, which was founded by human rights activist and poet Javier Sicilia, puts the death toll from Mexico's drug war at 70,000. EFE