Investigators swooped down Monday on a home only one-quarter mile from where a deadly arson wildfire was started last week and took three residents into custody for questioning, FOX News has learned.

Riverside County Sheriff's Department spokesman Sgt. Earl Quintana confirmed to FOX News the three — two young men and a young woman — are considered "persons of interest" in connection with their investigation of the Esperanza fire that killed four firefighters and critically injured another.

The three were later released, according to the Associated Press.

"We're trying to work through the leads that we have, and going through the process," Riverside County Sheriff Bob Doyle said.

Doyle cautioned that investigators would be interviewing a number of people in the case. Quintana said there have been no arrests.

Investigators entered the home just after noon PT (3 p.m. ET), and conducted an extensive search for evidence, including dusting for fingerprints, officials said.

Cabazon resident Robert Dunham told the Associated Press that in addition to the residents, sheriff's deputies took three bags of material from the home. The area is a quarter-mile from where the Esperanza fire started.

Another neighbor told FOX News one of the men taken into custody and placed in the back of a sheriff's patrol car was named "Jason," and described him as "a skin head."

Other nearby residents described the three young people as "troublemakers."

The raid included investigators from the Riverside County Sheriff's Department, the Cabazon Fire Department and the California Department of Forestry.

Investigators, including the FBI, have been searching since last Thursday for the arsonists responsible for starting the wildfire that killed four firefighters who were trapped when a wall of flames engulfed their engine while they were trying to protect a nearby home.

Officials immediately declared the fire the work of arsonists, and said that the firefighters' deaths was an act of murder.

More than 225 tips have been received by the Riverside County Sheriff's Department regarding the arson investigation, Doyle said.

Cabazon residents have told investigators that they saw two young men leaving the fire's ignition point.

"We're keeping a real tight lid on the investigation," said Michael Jarvis, a California Department of Forestry spokesman. "We're just asking people to call in with their tips."

Officials are offering $500,000 for information leading to the arrest of the arsonists.

Firefighters close to gaining the upperhand

The fire, fed by Santa Ana winds, continued to burn Monday, but officials said the winds had died and firefighters had gained the upper hand on the blaze that claimed nearly 41,000 acres.

"The weather has shifted in a very, very favorable way," Capt. Don Camp, a California Department of Forestry spokesman, said. "The winds are mostly gone and we're getting an onshore flow that's keeping the temperatures down."

The blaze still threatened wilderness plagued by drought and filled with dead trees. But fire officials said they believed they could get the blaze under control by Monday night if the winds stay away.

The favorable conditions have helped firefighters bring containment of the fire to 90 percent. Since it started around 1 a.m. Thursday, the fire has burned 63 square miles, or 40,200 acres, northwest of Palm Springs.

Fire officials were still concerned with the blaze's southeastern flank, which borders a wilderness area that hasn't burned in more than 30 years and has been devastated by a bark beetle infestation that has killed hundreds of trees.

"This is the only place the infrared shows any activity at all. This is also the place with the heaviest fuels we have," said fire analyst Timothy Chavez.

Injured firefighter battling for life, but improving

Pablo Cerda, 23, the firefighter who was critically injured with burns over more than 90 percent of his body, underwent surgery Friday to remove damaged skin. While his condition was not upgraded Monday, hospital sources said he was improving.

About 50 of Cerda's relatives gathered at the hospital, praying for him.

"They want everyone to know that Pablo's dream was to help people, and on Thursday morning, that's just what he was doing — protecting and serving," said Eddie Cortez, a family spokesman.

Vigils were held at several Southern California churches and fire stations for Cerda and to pray for the families of the fallen firefighters. Killed were Mark Loutzenhiser, 43, of Idyllwild; Jason McKay, 27, of Phelan; Jess McLean, 27, of Beaumont; and Daniel Hoover-Najera, 20, of San Jacinto.

Thirteen other firefighters suffered minor injuries battling the blaze.

More than 2,500 firefighters were involved in battling the blaze, which destroyed 34 homes, 20 out buildings and caused more than $8 million in property damage, to date, officials said.

The Associated Press contributed to this report