ING bank customers were again unable to use online banking services on Tuesday night, because of a renewed cyber attack.

The attack lasted around 20 minutes, ING said. A DDoS or denial-of-service attack involves bombarding a site with data traffic which makes it extremely difficult to reach.

ING internet banking services were also disrupted earlier on Tuesday as the bank took action to prevent it being vulnerable to attack.

ING online services were left in chaos at least twice last week, on Friday because of a massive cyber attack. The attacks on ING are being investigated by the police high-tech crime team.