Sept. 3 (UPI) -- Phoenix police have issued an arrest warrant for Dimas Coronado, who investigators believe killed his wife and another man.
Police believe the estranged husband kidnapped his two sons after killing their mother, Oralia Nunez, and friend Omar Gonzalez. Nunez, 24, was eight months pregnant.
The two were found at Nunez's apartment on Saturday morning. Shortly after, Phoenix police issued Amber Alerts for the missing boys -- 8-year-old Victor Coronado-Nunez and 5-year-old Jonathan Coronado-Nunez.
Originally, police said Coronado wasn't involved in the attacks, but later charged him with the deaths of his wife, Gonzales and the unborn child.
A vehicle belonging to Coronado was found after Nunez and Gonzalez were found by the woman's roommate, but the boys remain missing.
Authorities believe Coronado may be attempting to flee to Mexico with the boys. Police have asked Mexican authorities for help.
"An arrest warrant has been issued and he is considered armed and dangerous," Sgt. Armando Carbajal of the Phoenix Police Department said.
"We simply do not know where the children are at this time," Carbajal said. "We have reasons to believe Mexico was an option for the suspect as he had family there."
Nunez and Coronado had been married for nine years, but separated several months ago. Nunez was fighting for custody of the boys. A family friend told CBS News she was frightened of Coronado.
Authorities say Coronado may have switched vehicles and is now driving a green pickup with a camper shell and Mexican license plates.