SANTA ANA, Calif. (Reuters) - Authorities in Southern California have quadrupled the reward for information leading to the capture of an accused killer and two other men charged with violent felonies who continued to elude a manhunt four days after breaking out of jail.

Inmates Jonathan Tieu, 20, Bac Duong, 43, and Hossein Nayeri, 37, (L to R) are seen in an undated combination photo released by the Orange County, California, Sheriff's Department. The three inmates, an accused murderer and two other California prisoners, were still at large on Sunday after breaking out of the Orange County jail as a massive manhunt for the trio entered its third day, authorities said. REUTERS/Orange County Sheriff's Department/Handout via Reuters

The three escapees - Hossein Nayeri, 37, Jonathan Tieu, 20, and Bac Duong, 43 - slipped away early on Friday from the Men’s Central Jail in Santa Ana, about 30 miles southeast of Los Angeles, triggering an intense search across the region.

The Orange County Sheriff’s Department, which runs the jail and is leading the manhunt, has said all three men are considered extremely dangerous.

Authorities say the men cut through steel grating inside the detention center, climbed through a plumbing conduit and up to the jailhouse roof, then used bedsheets tied together to lower themselves four stories to the ground and vanished.

They were charged on Monday with felony escape, and sheriff’s officials appealed to members of Orange County’s Vietnamese immigrant community for help in locating the inmates.

Tieu, charged with a murder that authorities believe was gang-related, was described as a documented member of a Vietnamese street gang. Duong, who was being held on a charge of attempted murder, was characterized as an “associate” of a Vietnamese street gang.

Nayeri, who is of Iranian descent, has a conviction for homicide and is accused in a kidnapping and torture case, authorities said.

A $50,000 reward was initially posted by the FBI and U.S. Marshals Service for information leading to the capture of the three men. The Orange County Board of Supervisors voted on Tuesday to increase the size of the reward to $200,000, Supervisor Todd Spitzer said.

“Make no mistake about it, this board will allocate all resources available to capture these very dangerous criminals,” he said.

Orange County Sheriff’s Department Lieutenant Jeff Hallock said the men could be armed. He declined to disclose what mode of transportation they may be using.

Hallock also said authorities were investigating whether the prisoners had help inside or outside the detention center.

A disturbance in the jail during which a deputy was assaulted may have been concocted as part of a plan to delay an inmate head count on Friday night and buy the escapees more time to make their getaway, Hallock said on Monday.