(CNN)A search for potential mass graves from the 1921 Tulsa race massacre has ended without uncovering any evidence of human remains.

The test excavation at Tulsa, Oklahoma’s, Oaklawn Cemetery took 8 days and was part of a study to find human remains from the massacre, in which hundreds of Black people were brutally killed by White rioters. The effort had been set for March but was put on hold due to the coronavirus pandemic.

“This initial test excavation was the first of many efforts to find Tulsa Race Massacre victims and this is just the beginning of our work to bring healing and justice to the families,” Tulsa Mayor G.T. Bynum said in a statement released by the city Wednesday. “We remain committed to find out what happened to our fellow Tulsans in 1921.”

The site was chosen after an initial geophysical investigation identified a so-called “anomaly” consistent with a mass grave in what’s known as the Sexton area of the cemetery. The cemetery was closed to the public during the excavation, and forensic archaeologists were on hand to search for clues.

In a news conference Wednesday, State Archeologist Kary Stacklebeck described the test excavation as an “intermediate phase” meant to confirm whether there was a mass grave present before recommending a more complicated, full-scale recovery effort.

While no mass graves were discovered, the effort uncovered some artifacts dating to the 1920s, the news release said, most notably a bullet, two pairs of shoes and a buried road.

“At this point, we believe we have fully investigated this anomaly, and unfortunately we have not discovered the evidence of Race Massacre victims we were hoping to find,” Stacklebeck said in the city’s news release. “But we have learned a great deal about the cemetery itself, and this is information we can carry forward as we investigate future sites.”

The city said there were still multiples sites of interest and potential candidates for mass graves.

As many as 300 people were killed in the massacre

For decades, the massacre — often referred to as the Tulsa race riots — were largely unacknowledged.

The massacre has gotten more attention in recent years, particularly on its 99th anniversary last month, which occurred amid nationwide protests over racial injustice following the police killing of George Floyd in Minneapolis.

According to historic accounts, the riots were sparked by a confrontation between a Black resident and a White man among a group of angry White people demanding the lynching of a young Black man. A struggle ensued over the White man’s gun, and the White man was shot.

On the morning of June 1, 1921, White rioters flooded into the city’s Greenwood district — an economic hub then known as Black Wall Street. When it was over, more than 35 city blocks were burned, an estimated 1,200 homes were destroyed and more than 800 people were injured. Historians believe that as many as 300 people were killed, according to the Tulsa Historical Society and Museum.

Bodies were buried by strangers in mass graves while the victims’ families were detained under martial law, Scott Ellsworth, a University of Michigan historian who has long worked on the recovery of Tulsa massacre graves, previously told CNN.

Ellsworth, who was also part of Tulsa’s test excavation, added that the families were never told whether their loved ones died or where they were buried.

Chair of the Public Oversight Committee Brenda Alford said in the city’s news release on Wednesday that she had entered the effort with the “hope of continuing the work of generations before us to uncover the truth of the Tulsa Race Massacre.”

“I still have that hope,” she said. “I know that we are just at the beginning of a long-term investigation for truth, and that we have a powerful team assembled that will continue that work.”

CNN’s Kay Jones, Sara Sidner, Alaa Elassar and Elizabeth Wolfe contributed to this report.