Federal officials joined an arson investigation at Alaska Gov. Sarah Palin's church on Monday, days after an accelerant was poured around the exterior of the 2 1/2-year-old building, causing $1 million in damages.

Palin, who was not at Wasilla Bible Church when the fire broke out on Friday, told FOXNews' Greta Van Susteren she visited it with her husband Todd the day after. 

According to her spokesman, Bill McAllister, the governor told an assistant pastor that she was sorry if the fire was connected to the "undeserved negative attention" the church has received since she became the Republican vice presidential candidate in August.

Palin reiterated that sentiment late Monday.

"It's certainly a concern of mine," the Alaskan governor told Van Susteren via telephone from Juneau. "If there's anything I've done to bring negative attention to [the church], I'm sorry."

A small group was inside the church when the building was ignited, but no one was injured.

Asked if she was aware of any reason the church would be targeted or potential controversy, Palin recalled an insert in a bulletin for another church in Anchorage that dealt with "assistance or counseling in dealing with homosexuality."

The governor didn't elaborate on the insert, but said it "drew quite a bit of scrutiny."

Palin said homosexuals are welcome at her church.

"In fact, pastors at the church are quite open in terms of welcoming people," she said. "That's what this church is about."

Pastor Larry Kroon, meanwhile, said an apology from the governor was unnecessary.

"There's no need to apologize at all," Kroon told Van Susteren. "This fire won't change what we do. A considerable amount of the building is in great shape."

One churchgoer told FOXNews.com that the fire has lifted the spirits of church members.

"It was very upbeat, people were in good spirits," Rob Tracy said after Sunday services, which were held at Wasilla Middle School. "In one respect, people were reeling from the shock of the news, but in another respect, they were very positive. It felt like we had the whole family together yesterday. It's not often we have the full congregation together, but it felt like every single person was there.

"It was a feeling of unity, solidarity," Tracy said.

Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) are now the fifth agency to join the arson investigation, along with the Central Mat-Su Fire Department, Anchorage Fire Department, Wasilla Police Department and the State Fire Marshals Office

Tracy, who shuttled congregants to the school, said worshippers have "no information to even speculate on" regarding possible suspects.

"We're all kind of wondering what the investigators will learn," he told FOXNews.com. "We have nothing to go on, but the feeling is that perhaps it has to do with the Christian message itself, that perhaps someone has animosity to the basic Christian message."

During his sermon yesterday, Pastor Larry Kroon focused on messages of "faith, hope and love," Tracy said.

"And that really resonated," he said. "We will continue to be a church that lives the message of hope and expresses Christ's love."

But the timing of the fire, which occurred less than two weeks before Christmas, shocked and angered some worshippers, he continued.

"The fact that it's close to Christmas says more about the person who set this fire and their motivations," he said. "But it's serving to be more unifying for each of us."

A message on the church's Web site read: "Praise God that no one in the building was injured, and pray for us as we rebuild."