16 Percent of American Church Fires Are Intentionally Set, Stats Show Comes as federal and state authorities are investigating a South Carolina fire.

 -- Fires break out at churches and other "religious and funeral properties" in the US an average of 1,780 times in recent years -- about 34 a week -- and 16 percent of those were found to have been intentionally set, according to statistics from a non-profit fire protection group.

The scrutiny of church fires comes as federal investigators look into the cause of a fire at a historic black church in South Carolina that was previously burned down by a hate group.

Though the investigation into the fire that started at the Mt. Zion AME Church in Greeleyville on Tuesday night is only in its initial stages, sources close to the investigation have told ABC News that it does not appear to have been a criminal act. Additionally, there is no evidence to suggest that six other recent church fires across the south are racially motivated, a senior law enforcement source told ABC News.

According to statistics collected by the National Fire Protection Association, a non-profit "devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards," about 16 percent of fires at places of worship and funeral homes between 2007 and 2011 were intentionally set.

It was not clear what percentage of these fires, an average of 280 a year, were considered hate crimes.

By contrast, 30 percent were from cooking (most of which were "minor"), the top cause and another 16 percent were electrical. Candles and smoking accounted for smaller percentages, the statistics from the report, date June 2013, say.

Arson accounted for 25 percent of the property damage from fires, compared to 4 percent from cooking. The study defines a structure fire as "any fire that occurs in or on a structure...even if the fire was limited to contents and the building itself was not damaged."

Overall fires at churches declined from 3,500 in 1980 to 1,660 in 2011, the latest year for which statistics were available, a drop of about 53 percent.

Initial witness reports from the Mt. Zion fire suggested that the blaze may have been started as a result of lightning hitting the roof, but local and federal authorities involved in the investigation were careful not to reveal any details at a press conference this morning.

"We haven't ruled anything in or anything out at this point,” Bureau of Alcohol, Tobacco and Firearms special agent in charge Craig Chillcott said. “We're going to let the case dictate.”

The ATF released a statement on Tuesday saying that they are investigating five fires that were reported in as many states in the past two weeks though they say they have no reason to believe the series of church fires were racially motivated or related.

The fires came amid heightened tensions caused by the racially charged massacre at a Charleston, South Carolina church that left nine people, including a pastor dead and an uproar over the Confederate flag flying at the South Carolina statehouse.