Three victims of the 1921 Tulsa Race Massacre, whose remains were exhumed along with those of eight others, were found to have gunshot wounds, investigators announced on Friday, in the latest findings from research about one of the worst racial attacks in U.S. history.

G.T. Bynum, the mayor of Tulsa, Okla., announced in 2018 that the city would begin searching for and analyzing the bodies of victims of the massacre to learn more about their identities and causes of death.

Between 36 and 300 people are thought to have died during the massacre, officials have said, however only 26 death certificates were issued in connection to it.

“The people that we are searching for, our fellow Tulsans, they’re not just names in history,” Mr. Bynum said at a news conference on Friday. “These are our neighbors who were murdered in horrible ways.”

Investigators are looking for “simple wooden caskets” that fit a variety of parameters that could indicate a possible victim of the massacre, according to Kary Stackelbeck, a state archaeologist.

“Two of those gunshot victims display evidence of munitions from two different weapons, meaning that those two individuals were shot with at least two different kinds of arms,” Dr. Stackelbeck said. “The third individual who is a gunshot victim also displays evidence of burning.”