MEXICO CITY — Ten guards and four inmates were killed early Sunday when gunmen in armored vehicles attacked a state prison in Ciudad Juarez across the border from El Paso, Texas, according to state officials. The Chihuahua state prosecutor’s office said in a statement that around 7 a.m. various armored vehicles arrived at the prison and gunmen opened fire on guards. Shortly before Sunday’s attack on the prison, municipal police were attacked and managed to capture four men after a pursuit, according to the state prosecutor’s office statement.