Gunmen ambushed two police vehicles at a busy intersection in Ciudad Juarez on Friday, killing six officers and a 17-year-old girl who was passing by, authorities said. Chihuahua state spokesman Enrique Torres Valadez said five of the six police officers were federal, and one was municipal. Authorities said the police officers in the vehicles were distracted by someone selling items on the street when the gunmen opened fire. The assailants then fled in three vehicles. Investigators said they don't know why the officers were shot, although they don't believe they were targeted because of any recent arrests they had made. No one has been arrested but police said they have recovered two of the three cars used in the shooting. Ciudad Juarez is one of the world's deadliest cities, and a two-year turf battle between drug cartels has left more than 5,000 people dead. Elsewhere, police in Guerrero said they found the bodies of five men who had been shot to death lying on a dirt road near Chilpancingo, the capital of the Pacific coast state. Three of the men were brothers, all in their 20s. The state has been a major battleground for warring cartels, including the Beltran Leyva gang, but it was not clear whether the shootings were part of the ongoing drug violence. In Morelos state, federal police and the Mexican army raided two ranch homes and arrested 15 men near the town of Amacuzac. Those arrested were taken to Mexico City in a helicopter. The men are suspected of working for Jose Gerardo Alvarez Vazquez, who was arrested in Mexico City on Wednesday, said Ramon Pequeno, the head of the anti-narcotics division of Mexico's federal police. Pequeno said the men provided security and carried out killings for Alvarez Vazquez and his partner Edgar Valdez Villarreal, a U.S.-born enforcer known as 'La Barbie.' Authorities say Alvarez Vazquez and Valdez Villareal are battling for control of the Beltran Leyva cartel. An estimated 22,700 people have been killed in Mexico's drug war since December 2006. 