Updated at 9:25 p.m. ET
Federal officials are investigating a fire that started overnight at the site of a new Islamic center in a Nashville suburb.
Ben Goodwin of the Rutherford County Sheriff's Department confirmed to CBS Affiliate WTVF that the fire, which burned construction equipment at the future site of the Islamic Center of Murfreesboro, is being ruled as arson.
Special Agent Andy Anderson of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives told CBS News that the fire destroyed one piece of construction equipment and damaged three others. Gas was poured over the equipment to start the fire, Anderson said.
The ATF, FBI and Rutherford County Sheriff's Office are conducting a joint investigation into the fire, Anderson said.
WTVF reports firefighters were alerted by a passerby who saw flames at the site. One large earth hauler was set on fire before the suspect or suspects left the scene.
The chair of the center's planning committee, Essim Fathy, said he drove to the site at around 5:30 a.m. Saturday morning after he was contacted by the sheriff's department.
"Our people and community are so worried of what else can happen," said Fathy. "They are so scared."
The fire was smoldering by the time Fathy and the center's imam, Ossama Bahloul, had arrived. Fathy was told that responders had smelled gasoline near the fire.
Fathy was later contacted by members of the FBI and the Department of Homeland Security, who told him the incident was under investigation and to remain calm.
Digging had begun at the site, which was planned as a place of worship for the approximately 250 Muslim families in the Murfreesboro area, but no structure had been built yet, according to Saleh Sbenaty, a member of the planning committee and a professor of engineering technology at Middle Tennessee State University.
"This is a shock," said Sbenaty. "We've had small act of vandals. But this is going to be a crime and whoever did it, they should be punished to the full extent of the law."
The center had operated for years out of a small business suite. Planning members said the new building, which was being constructed next to a church, would help accommodate the area's growing Muslim community.
"We unfortunately did not experience hostilities for the 30 years we've been here and have only seen the hostility since approval of the site plan for the new center," said Sbenaty.
Opponents of a new Islamic center say they believe the mosque will be more than a place of prayer; they are afraid the 15-acre site that was once farmland will be turned into a terrorist training ground for Muslim militants bent on overthrowing the U.S. government.
"They are not a religion. They are a political, militaristic group," Bob Shelton, a 76-year-old retiree who lives in the area, told The Associated Press.
Shelton was among several hundred demonstrators who recently wore "Vote for Jesus" T-shirts and carried signs that said "No Sharia law for USA!," referring to the Islamic code of law.
Others took their opposition further, spray painting a sign announcing the "Future site of the Islamic Center of Murfreesboro" and tearing it up.
Earlier this summer opponents criticized the planned mosque at hearings held by the Rutherford County Commission, as supporters held prayer vigils.
At one such prayer vigil, WTVF reported opponents speaking out against construction.
"No mosque in Murfreesboro. I don't want it. I don't want them here," Evy Summers said to WTVF. "Go start their own country overseas somewhere. This is a Christian country. It was based on Christianity."