Ciudad Juarez, Chih - At least six people were killed -- including a quadruple murder -- in Juárez on Tuesday.
Four people, including a 16-year-old boy, were killed in a shooting outside a home in east Juárez, said Chihuahua state police.
Three victims died on the street after shooters fired 24 rounds from an AK-47 about 11:45 a.m. on Toronja Roja street, police said.
Police identified the dead as Israel Díaz Guerrero, 21; José Luis Carrasco Ramos, 16; Arturo Astorga Mora, between 35 and 40 years old; and Victor Amaya, who was in his 20s.
About 3 p.m., a man was shot and killed near Avenida de las Torres in the east part of the city.
The man had not been identified.
At 4:15 p.m., another man, identified as 21-year-old Fernando Becerra Dominguez, was fatally shot in the head on Isla Hawaii street in west Juárez, police said.
Four .22-caliber casings were found.
On Monday, hundreds of Mexican soldiers rode into Juárez as part of a regular rotation of army units, Coordinated Operation Chihuahua officials said.
The soldiers arrived in convoys of green pickups, cargo trucks and Hummers to take part in anti-drug operations in the troubled city.
The soldiers are from the 4th, 78th, and 98th Infantry Battalions and the 2nd Independent Infantry Battalion, all from the Mexico City area.
The Mexican military rotates units every 60 days in an effort to prevent corruption and bring in fresh soldiers.
Thousands of soldiers and federal police are in Juárez as part of the federal government's efforts to quell violent crime.
The presence of the army has also led to complaints about unlawful searches of homes, illegal arrests and other civil-rights violations.
About 4,700 people have been killed in Juárez since January 2008 due in because of a war between the Sinaloa and Juárez drug cartels.