Texas (KXAN) — More than 10,000 mail-in ballots were not included in Harris County’s Election Night results, the Secretary of State’s Office found. Those votes will have to be added to the final count.

The Texas Secretary of State’s office says they reached out to Harris County Friday after noticing a more than 10,000 vote difference on its Election Night reconciliation form. Harris County is the most populous county in Texas, encompassing Houston.

Harris County officials say they went through and found more than 10,000 mail-in ballots had been scanned into their system, but were not transferred and counted to the unofficial results.

Harris County said roughly 6,000 of those ballots were Democratic and 4,000 were Republican. They sent out the following statement:

“We have reached out to and are working in coordination with the Secretary of State’s Office as we investigate the missteps that took place in this process. We are committed to full transparency and will continue to provide updates as they are available. While we understand the seriousness of this error, the ability to identify and correct this issue is a result of a lengthy, rigorous process and is a positive example of the process ultimately working as it should.”

The Secretary of State’s office responded and said, “We agree that this is the process working as it should. Additionally, it’s only because this Election Night reconciliation form is now required for all 254 counties that we were able to identify the discrepancy and work with the county to find out exactly what happened.”

Harris County also struggled on Election Day.

Election officials alerted the Texas Secretary of State’s Office on March 1 that they were experiencing delays in vote counting.

After delays and intervention from county parties to impound election records, the elections division finally released its primary election results early Thursday morning.