A dozen prisoners escaped Friday from a jail in downtown El Salvador, but four were quickly recaptured. Officials were still searching for the other eight.

One of the prison's guards is in custody for allegedly helping the group, top police official Cesar Flores said.

Flores said the prisoners tied their shirts together to make a rope and used that to climb to the jail's roof before dawn. They then fled by jumping to other buildings.

"Neighbors in the area called 9-1-1 to report that there were several suspects on the roofs, and we believe they were the escaped inmates," he said.

The jail at the Isidro Menendez judicial center in downtown San Salvador was holding 80 inmates at the time of the escape. Most are awaiting trial.

Those who escaped were members of the violent and feared Mara Salvatrucha street gang.

Police say El Salvador has about 13,500 Mara gang members, many of whom are involved in kidnappings, extortion rings and other crimes.