The victims were studying engineering at Monterrey Tech University, according to Nuevo Leon state Attorney General Alejandro Garza y Garza.
Army officials mistakenly told state prosecutors that two suspected gunmen died in Friday's clash, Garza y Garza said late Saturday.
Monterrey Tech University rector Rafael Rangel said in a news release that both students had scholarships for academic excellence and had been at the college minutes before the shootout.
On Sunday, gunmen targeting the police chief of a town outside Monterrey killed his bodyguard and wounded three other people, said a Nuevo Leon State Investigative Agency spokesman, who was not authorized to give his name.
The spokesman said it was not immediately clear if Santa Catarina police chief Rene Castillo was among the wounded.
Phones rang unanswered at local government offices at Santa Catarina.
There has been a series of shootouts over the past week in the area around Monterrey, Mexico's third-largest city and an industrial hub. Gangs last week also used abandoned cars to block several main roads in the city in an attempt to impede military patrols.
The federal government has said gangs are lashing back over the arrests of suspects tied to Beltran Leyva cartels and other organizations in the area.
