MEXICO CITY – Assailants armed with assault rifles burst into a hospital in the northern Mexican state of Durango and killed three men being treated for gunshot wounds, the state Attorney General’s Office said Tuesday.

Wounded last Saturday on the streets of Villa Union, the three men received initial treatment on the scene from the Red Cross and were then taken to the town’s hospital.

Their attackers followed them to the hospital and finished them off there, the AG office said, adding that no hospital employees were hurt in the incident.

The use of assault rifles indicates the killings were related to organized crime.

Late Monday, Mexico’s defense department announced the arrest of a reputed killer-for-hire accused in 30 murders and 14 kidnappings.

Eduar Vera Arias, 30, a native of the southern state of Chiapas, was detained by army troops near the northern border city of Ciudad Juarez, the department said in a statement.

Vera admitted to having killed 30 people on the orders of the Juarez drug cartel, authorities said.

In a related matter, the Chihuahua state Attorney General’s Office said that 12 men were killed in separate gangland incidents in Juarez, Mexico’s most violent city.

Four of the victims were gunned down Sunday night at various points in the city, which lies just across the Rio Grande from El Paso, Texas.

An attack in the wee hours of Monday at Gabino’s bar left five dead, while three other men were slain later in the day in the western part of Ciudad Juarez.

The city has witnessed more than 1,700 murders so far this year, according to unofficial press tallies, topping the 1,600 homicides recorded for all of 2008. The killings are largely blamed on a battle between Mexico’s powerful drug cartels for control of smuggling routes and distribution networks.

Drug-related violence has claimed nearly 15,000 lives in Mexico since December 2006, when newly inaugurated President Felipe Calderon began deploying tens of thousands of soldiers and federal police to fight the traffickers and their heavily armed enforcers, many of them army veterans.

A dispute between rival crime organizations is also thought to be behind a weekend clash in the southern border state of Chiapas that left seven people dead and two others wounded, the state government said Monday.

“One of the armed groups was composed of Guatemalans, who fled toward Mexico’s border with Guatemala,” authorities said in a statement about Sunday’s confrontation in La Union, a town in the Lacandona Jungle.

Authorities are working to identify the dead, the statement said.

Chiapas is home to several criminal groups vying to dominate the trade in drugs, weapons and undocumented migrants across the Guatemala-Mexico border. EFE