Nine baptist churches have been torched in just five days in Alabama, where images of smoldering buildings evoke painful memories.
Federal crime-scene investigators are sifting through the charred remains of four churches that were found on Tuesday. The latest fires occurred within a week after five other blazes were ruled arson.
Officials fear that if an arrest is not made soon, the fires may continue to rage.
"We've got a maniac running around burning church buildings," said Johnny Isaac, sheriff of Greene County, where the latest fires occurred.
The pastor of Morning Star Baptist Church said that early Tuesday someone forcibly opened a side door and deliberately set the house of worship on fire.
"The person that did this is a person that is full of hate. A person that is full of hate doesn't know God," the Rev. James Posey said.
All the four latest burned churches were within a 30-mile radius and about 60 miles from the five churches that were burned last week. Investigators said there were two sightings of two white males in a dark sport utility vehicle racing away from one of the churches.
Investigators say they are making progress with the case.
Scores of local police and dozens of federal agents, including the FBI and more than 56 investigators from the Bureau of Alcohol, Tobacco Firearms and Explosives are on the scene.
Sources tell ABC News a flammable liquid was used to set the five fires last week in Bibb County; the Morning Star Baptist Church in Boligee was also apparently set with a flammable liquid.
Investigators are taking samples from the rubble of all the churches that burned overnight to determine whether what caused those fires is similar to what caused the five fires last week. Evidence from the crime scenes is being flown to the ATF National Arson Laboratory in Atlanta.
"We worry as time passes as we don't put these folks away or find these people who are responsible for this, that we will continue to have these, " said Chip Burrus, acting assistant director of the criminal division of the FBI. "There's a lot of baptist churches that are looking around thinking: 'Am I next?'"
This is the largest cluster of church fires since arsonists burned 28 places of worship in nine southern and southwestern states over 17 months in the mid-1990s. Two people were charged.
"It's definitely a sensitive issue. I mean, that's the fabric of our community, any time that there's an attack on a church or a house of worship it pulls that community," said Larry Ford, the ATF's assistant director. "It really attacks that community."
Burrus said investigators were working on the assumption that all nine of the Alabama church fires were connected.
"Clearly there's a suspected link," Burrus said. "Common sense tells you there is a clear indication these fires are going to be linked."
"We are able to get a lot of physical evidence and clues in there because it's not totally damaged, and that gives us an indicator also of how the fires were set," said ATF agent Jim Cavanaugh.
Federal agents say solving this is now their No. 1 priority, and congregations across Alabama are keeping watch to protect their churches. The state and federal governments are offering rewards that total $10,000. The arsons are not thought to be racially motivated because the burned churches had both white and black congregations.
"The whole thing is strange. What the motives are we don't know. But we're going to investigate it," said Pickens County Sheriff David Abston. "We've called the experts."
The FBI said it was looking into whether the Bibb County fires were a civil rights violation under laws covering attacks on religious property.
Agents said Tuesday that they were looking for a dark-colored SUV -- possibly a Nissan Pathfinder -- in connection with the blazes.
ABC News' Pierre Thomas contributed to this report.