Officials in Los Angeles said they are investigating a mail-in ballot box and ballots that were burned as well as a vandalized Los Angeles County voting center, according to the Los Angeles County Registrar-Recorder and County Clerk’s office.

In one incident detailed by the office, vandalism was discovered at the Vote Center at Cesar E. Chavez Park on Sunday morning. Election workers and officials responded to the incident immediately, and voting operations weren’t disrupted, the office said in a statement.

The office said that in the other incident, officials discovered “a limited number of Vote by Mail ballots that appeared to have sustained fire-related damage inside” a ballot drop-box at the Department of Public Social Services-Civic Center in Los Angeles. The fire damage was observed “during routine ballot collection procedures,” the office also said.

“Preliminary information indicates the incident was isolated and involved a small number of ballots, as it occurred between the most recent scheduled collection and the following morning’s retrieval,”  the statement said.

The elections office said it filed a relevant report with the Los Angeles Police Department and vowed to subsequently “fully cooperate with any investigation into the cause and circumstances of the incident.”

According to the statement, both incidents are being reviewed, and officials are now attempting to identify any voters who may have been impacted. Voters whose ballots were burned in the drop-box “will be contacted directly and provided information about available options, including replacement ballots if necessary,” it added.

“Our responsibility is to protect voters and ensure every eligible voter has the opportunity to cast a ballot,” Dean Logan, the Los Angeles registrar-recorder and county clerk, said in a statement about the matter. “Any attempt to interfere with voting or election operations is taken seriously. We will continue working closely with law enforcement and other partners to safeguard the voting process and ensure voters can participate with confidence.”

People who may see suspicious activity involving ballots or election matters are advised to report it to the county clerk and registrar’s office.

The county further said that it “takes all incidents involving election operations and materials seriously and will report, refer, and fully cooperate with law enforcement and other appropriate authorities when warranted,” adding that federal and state laws offer criminal penalties for people who damage or tamper with ballots, voting equipment, election facilities, or election materials.

The incidents come around a day before the primary election for the hotly contested mayoral race in Los Angeles as well as statewide races. In the Los Angeles race for mayor, reality TV personality Spencer Pratt is hoping to turn his insurgent campaign into a surprise upset of Democratic Mayor Karen Bass. The two are tightly clustered with Nithya Raman, a progressive member of the City Council running to Bass’s political left.

If no mayoral candidate receives a majority of the vote in Tuesday’s primary, the top two will advance to a general election in November.

For the California governor’s race, former Fox News TV host and political adviser Steve Hilton is urging Republicans to unite behind him as he fights for one of two spots in the November election alongside two Democrats, billionaire climate activist Tom Steyer and former state attorney general and former U.S. Health Secretary Xavier Becerra.

The Associated Press contributed to this report.