Major telecom A1 Croatia said on Wednesday that they have been target of a hacking attack in which personal data of some of its users had been compromised. The company said they have reported the incident to Croatian police, and added that no information about their users bank accounts or credit cards has been breached, as they are stored in a separate database.

The company said that the names, addresses, personal identification numbers, and phone numbers of “less than 10 percent of A1 Croatia users” have been potentially affected. In a press release, A1 said they were working on establishing all the facts related to the security incident, and that they would notify directly all users whose personal data had been compromised.

They added that police IT experts are now involved in efforts to identify the perpetrators. They also notified the Hakom market regulator and the national personal data protection agency Azop of the incident.

A1 said that they apply “highest security and data protection standards” and that they would continue with additional investments to improve the security environment.

“A re-occurrence of this breach is not possible, and the incident did not and will not have any effect on the services we provide to our clients,” A1 Croatia said.