University officials in crime-ridden Ciudad Juarez said Wednesday they are planning a protest march after the murder of a medical student who was forced to kneel then shot in the head.

Officials at the Autonomous University of Ciudad Juarez said 20-year-old Juan Antonio Chavez was killed at dawn Wednesday.

University spokesman Arturo Pedraza said Chavez was a student and a Red Cross paramedic. No motive was given for his killing.

Chavez's death follows the murder of 17-year-old student Alfredo Franco, who was killed by a group of gunmen a few days ago. Pedraza said the university is sponsoring a march Sunday to protest the violence against their students.

Ciudad Juarez is Mexico's deadliest city. More than 1,900 people have been killed this year as drug cartels battle for control.

In Acapulco in southern Guerrero state, authorities said they found the bodies of two men along with written messages accusing them of kidnapping.

The bound bodies had been dumped in different locations, police said Wednesday. But both were accompanied by a note that said, "This will happen to all the kidnappers."

State police said they were investigating the killings.

In a separate attack, assailants threw a grenade at a state police station in the town of La Union Wednesday. The station and a patrol car were damaged by the blast, but no one was injured, police said.

Several recent attacks have targeted police in La Union, located north of the Pacific resort cities of Acapulco and Zihuatanejo.

In November, one policeman was killed and four were wounded when gunmen opened fire on two patrol vehicles. And the remains of two police officers were found inside black plastic bags there in June.

The Pacific coast state of Guerrero has been a battleground in the drug-fueled violence that has cost almost 14,000 lives since President Felipe Calderon launched an offensive against drug cartels in late 2006.