DBS and Citibank banking services in Singapore were brought offline Saturday afternoon due to an outage at an Equinix data center.

The cause of the outage is not yet known. The issue also appears to have impacted other services in the Philippines, Hong Kong, and India, with users complaining about issues with Facebook, Instagram, WhatsApp, and Call of Duty.

"A technical issue occurred at one of our data centers in Singapore that raised the temperatures in the data center and impacted some customers' operations," Equinix said.

The colocation and interconnection giant said that it would conduct a "thorough investigation" into the incident.

Update: In a statement, the company said that the issue was with its chilled water system.

The Monetary Authority of Singapore (MAS) said that it was aware of the outage, and was conducting its own preliminary investigation.

DBS users have experienced multiple outages in the past year, although previous issues appear unrelated to the Equinix data center.

Those outages led MAS to impose restrictions on the company and direct it to conduct a comprehensive review, including an assessment of the adequacy of management oversight, staff competencies, operational processes, system resiliency, and architecture design for its digital banking services.

That came after an earlier restriction due to a February 2022 outage.