(CNN) -- In what authorities described as an ambush-style, noontime attack by armed gunmen, three police officers were killed Wednesday in downtown Ciudad Juarez, Mexico, while patrolling outside an elementary school, a municipal police spokesman told CNN.
"Unfortunately, there was an attack and three of our colleagues were killed," Municipal Police spokesman Adrian Sanchez Contreras said. "There were two men and two women. One of the women lured the police vehicle onto the school grounds and that's when the attack occurred," Sanchez added.
The suspects were in at least two vehicles when the attack occurred, according to Sanchez. The victims were a 24-year-old female officer and two male officers, one 26 and the other 33 years old.
Since October 14, when Juarez Mayor Hector "Teto" Murguia began his term as the city's new mayor, 25 police officers have been assassinated, Sanchez said -- an average of almost an officer killed every other day since Murguia has been in office.
Local journalists say recently there's been word that the two cartels engaged in a violent turf war since 2008 -- the Juarez and Sinaloa cartels -- have been negotiating a truce.
"The local gangs in the area are unhappy with the agreement. The violence we're seeing now is like a cleansing against those who are opposed to an agreement," local journalist Arturo Chacon said, referring to the complicated web of alliances and suspicions on all sides in crime-plagued Juarez.
On Saturday, a group of armed men ambushed a police car and killed four municipal officers inside.
On Monday, two armed attackers burst into a kindergarten and set fire to the school building in the violence-plagued border city of Juarez, state media reported. There were no reports of injuries.
Police say the suspects left a message saying the school had not paid a protection fee, which they had demanded from teachers two weeks ago to prevent attacks against the children, the state-run Notimex news agency said Monday.