GREENVILLE, Miss. — Somebody set the fire that heavily damaged an African-American church that was also spray-painted with the phrase “Vote Trump,” and an $11,000 reward is being offered for information leading to the conviction of whoever did it, a Mississippi fire chief said Wednesday.

The FBI has opened a civil rights investigation of the Tuesday night fire at the 200-member Hopewell Missionary Baptist Church, and Greenville Mayor Errick Simmons called the fire and graffiti a hate crime.

Officials announced the reward and the investigators’ conclusion that the fire was arson at the church, Greenville Fire Chief Ruben Brown Sr. said in a telephone interview with The Associated Press.

The church’s beige brick walls still stand, but the pulpit and pews are burned black, and soot stains the brick above and next to some windows. Brown estimated that it was “80 percent destroyed.”

“It definitely will have to be reconstructed from front to back,” he said.

Simmons called the arson a “heinous, hateful, cowardly act.”

“We consider it a hate crime … because of the political message which we believe was intended to interfere with worship and intimidate voters,” Simmons said. “This act is a direct assault on people’s right to freely worship.”

The mayor said the FBI and the Mississippi Bureau of Investigation are assisting the investigation in the Mississippi River city, where about 78 percent of the 32,100 residents are African-American.

Mississippi’s top elections official, Secretary of State Delbert Hosemann, a Republican, said people shouldn’t jump to the conclusion that the church was vandalized for political reasons. Initial reports suggest “this is not of a political nature,” he told WDAM-TV.

The culprits should be prosecuted “to the fullest extent of the law,” he said.

State FBI spokesman Brett Car said the agency is “working with our local, state and federal law enforcement partners to determine if any civil rights crimes were committed.”

He did not comment on whether it was being investigated as a possible hate crime. “At this point, it is too early in the investigation to determine what type of crime this could be,” he said.

Gov. Phil Bryant, a Republican who has been campaigning for his party’s presidential nominee Donald Trump, said “we expect a suspect will be identified and brought to justice.”

“First, anyone who burns a place of worship will answer to almighty God for this crime against people of faith. But they should also answer to man’s law,” Bryant’s statement said.

U.S. Rep. Bennie Thompson, a Democrat whose district includes Greenville, said the fire and graffiti “harkens back to a much darker day in Mississippi.”

“The political message of the vandalism is obviously an attempt to sway public opinion regarding the upcoming election,” he wrote in an emailed statement. “I encourage all citizens not to be deterred by this cowardly act and exercise your right to vote at the ballot box.”

The Mississippi chapter of the NAACP released a statement Wednesday night saying the fire was reminiscent of a dark period in the state’s history.

“During the historically black church’s 111-year history, Hopewell served as a meeting place for organizers during the civil rights movement,” the statement said. “It is important to remember this same violent action was taken to intimidate and impede African-Americans from voting in the 50’s and 60’s.”

Brown said water from the hoses and heat from the fire also damaged the church’s kitchen and the pastor’s study. It was put out within 12 minutes, but it took an hour and a half to extinguish hot spots, he said.