The Singapore division of life insurance firm AXA Insurance has reportedly suffered a data breach, after hackers stole roughly 5,400 customers' personal information from its Health Portal.

Numerous news outlets, including Singapore's own The Straits Times, have reported that customers' email addresses, mobile phone numbers, and birth dates were exposed in the breach, but not health and claims details or financial information.

AXA Singapore reportedly began informing affected customers of the breach on Sept. 7.

The Straits Times further reported that AXA Singapore chief executive officer Jean Drouffe said the portal was "now secure," adding that the firm has advised customers to contact the authorities if they believe they were the target of phishing attempts potentially stemming from the breach.

It has not been revealed when the breach took place. The Monetary Authority of Singapore is reportedly investigating the incident.