After the major attack on a prison in Mexico that killed numerous people, more people were killed while pursuing the attackers. Two prosecutors and five suspected criminals were killed Monday, according to authorities in the northern state of Chihuahua.

An armed commando attacked the prison in Ciudad Juárez on New Year’s Day, enabling 25 prisoners to escape. According to Defense Minister Luis Cresencio Sandoval, ten guards, seven prisoners and two attackers were killed.

In the detention center, members of various criminal gangs and drug cartels are held in separate cell blocks. Among those who escaped was drug lord Ernesto Alfredo Piñon, known as “El Neto”, who was sentenced to more than 200 years in prison in 2010 for murder and kidnapping.

The city of Ciudad Juárez, with a population of 1.5 million, lies on the border with the USA and has suffered for years from the violence of rival drug cartels fighting for control of smuggling routes into the USA.