(CNN) After yet another suspected arson at a St. Louis-area church, authorities are continuing their hunt for those responsible while making a promise: "Whoever this person is, they've picked a fight they can't win."

That's what St. Louis Metropolitan Police Chief Sam Dotson told religious and civic leaders on Wednesday, hours before someone set fire to the Shrine of St. Joseph in the eastern Missouri city.

While it occurred in a different neighborhood and wasn't necessarily at a predominantly black church (though it is in a mostly African-American neighborhood), that predawn Thursday blaze is the seventh one to strike the general area in about two weeks.

The arsons have gotten the attention of firefighters and police, not to mention local leaders determined to stay strong and stay together as a community.

"We are sending a message ... that you can burn down the building, but you cannot break our body," the Rev. David Triggs, whose New Life Missionary Baptist Church was among those targeted, said at Wednesday's gathering. "And we will not lose our voice."

Pointing to the absence of surveillance cameras, Dotson told reporters early Thursday that whoever set the Shrine of St. Joseph fire "did some research, scouted the area out and knew that they could get in and get out without possibly being seen."

Why they did it is another matter.

Local authorities have been very vocal about their desire to catch the arsonist or arsonists, offering a reward and sending out special patrols around churches.

.@ChiefSLMPD-"We need anyone who has info to come forward." We have increased patrols around churches & will remain vigilant in those areas. — St. Louis, MO Police (@SLMPD) October 21, 2015

But they have little to offer about a possible motive.

"It can be everything," St. Louis Fire Chief Dennis Jenkerson told reporters Thursday outside the Shrine of St. Joseph. "It can be somebody who has got a beef against the church, or somebody who might have had some mental issues. It runs the gamut (and we may not know) until we actually catch the person or persons."

Different neighborhood, but similar to 6 other fires

Founded in the early 1840s by Jesuits in a neighborhood that then mostly consisted of German immigrants, the Shrine of St. Joseph has a special place in the history of St. Louis and especially the Catholic Church there. It's open to tours showcasing intricate artwork, statues and other details, and also boasts "the only authenticated miracle in the Midwest" -- the recovery of German immigrant Ignatius Strecker from a monthslong illness after his prayers to (future saint) Peter Claver and a blessing at the church.

Today, the church sits in the Columbus Square neighborhood -- an area that, according to 2010 Census findings , is about 90% African-American. The parishioners at the Shrine of St. Joseph, however, are mostly white, according to CNN affiliates KMOV and KTVI.

As Jenkerson noted, it is in a different neighborhood from the other six churches -- all of them predominantly black -- that were targeted over a recent 11-day period. And this time, the fire occurred at the rectory building, not in the church itself.

But there are also similarities between what happened at the Shrine of St. Joseph and the other churches.

Jenkerson said Thursday's fire occurred at a double-door entry, causing "very similar type of damage" to that of the other arsons. And, as in those other cases, no one else was there when this fire was set.

"(The fire was) small, contained (and) didn't take as much to put out," the fire chief said. "But it's very, very disturbing."

Priest: 'Wake-up call' about racism in St. Louis

The fire came hours after the community gathering at New Northside Missionary Baptist Church, which also had its own front door recently scorched.

"Our biggest concern is for whomever is doing this," the Rev. Roderick Burton from that church told CNN. "We want them to get help. We want them to stop, absolutely, and I think people would like to know what is the motivation behind it.

People of all races and faiths attended Wednesday's service at New Northside Missionary Baptist, and they didn't shy away from the possibility that racism may have spurred the arsonist to lash out. The Rev. Mike Kinman, an Episcopal priest at St. Louis' Christ Church Cathedral, who is white, was among them.

"Holy God," Kinman said, "if we ever needed a wake-up call to believe that racism is alive in St. Louis -- if this is not it, I don't know what it could be."

Dotson said at the same church service that, whatever the true motivation, "it's impossible to ignore that this kind of crime aggravates old wounds, old wounds that were never properly or fully healed."

"When someone attacks places of worship in our community, they attack the whole concept of civil society, aiming violence precisely at the places where people are at their most decent and their most peaceful," the police chief added.

But they won't get away with it, he promised.

"Whoever is out there trying to scare us, they have underestimated the power of that decency and the strength of our shared desire for peace," Dotson said. "... Whatever they think they're trying to accomplish, they will not succeed."