OCBC Bank experienced a service outage yesterday night, with users reporting that the bank's automated teller machines (ATMs), online banking system, 24-hour hotline and credit card transactions were all down.

Around 9pm yesterday, many users on various social media platforms began complaining that different aspects of the OCBC banking system were down.

The bank posted on Facebook at about 9.50pm that it was "experiencing network issues".

ATM services were restored by 11.32pm, while all banking services were back to normal by 12.30am, said the bank.

Mr Johnny Chan, 30, a systems programmer was one of many affected customers.

He had dined at a Thai Express outlet in Compass One shopping mall and tried to pay for his meal, which cost about $38, but all means of card payment - PayWave, Nets and Visa - did not work.

He said: "I had only an OCBC card with me so the manager allowed me to go to the ATM to withdraw money, but the ATM declined my withdrawal too.

"I had to call my wife to come over and pay for the meal. It was very embarrassing."

Many customers complained about their own experiences beneath an OCBC Facebook post about the network issues.

Facebook user Wilson Tay said: "I also was briefly stuck at Sheng Siong as I had only OCBC cards and both were declined at the time. Luckily, I had some cash, otherwise it would have been awkward."

The bank's 24-hour hotline also seemed to be down. When dialled, only a repetitive beeping sound could be heard.

Customers who tried to log into their online banking accounts were also unable to access the system as the login page appeared to have trouble loading.

Mr Samuel Tsien, group chief executive officer of OCBC Bank, said the bank is investigating the root cause of the technical problem.

"I sincerely apologise for the inconvenience and I am grateful for the patience and understanding of our customers."