A technology company whose products are used by U.S. states and counties to share election data warned clients in an email that an unknown party had hacked its internal phone systems, according to a copy of the email seen by Reuters. Tyler Technologies, whose platforms are used by elections officials to display voting results, among other tasks, said it did not believe clients’ software had been breached.

The company is a major provider of emergency management and other programs to U.S. counties and municipalities. Tyler confirmed the breach in an email to Reuters but did respond to questions.

The FBI and the Department of Homeland Security warned this week that foreign hackers might attempt to access and alter websites reporting election results. Neither responded to requests for comment after East Coast working hours. In the email to customers, Tyler said there had been a “security incident involving unauthorized access to our internal phone and information technology systems by an unknown third party …”

The email did not say what internal systems were breached. “We currently have no reason to believe that any client data, client servers, or hosted systems were affected,” it said.