A luxury resort operator in Singapore said Tuesday that the personal data of about 665,000 members of its shopping loyalty program had been hacked.

The breach of Marina Bay Sands was the latest in a string of major cybersecurity incidents reported in the city-state.

Last week public healthcare institutions had their internet access disrupted by a flood of malicious traffic in a so-called distributed denial of service (DDoS) attack.

Marina Bay Sands, which is owned by US casino giant Las Vegas Sands, said it became aware of the "data security incident" on 20 October, according to an email sent to some customers on Tuesday and seen by AFP.

"Investigations have since determined that an unknown third party accessed customer data of about 665,000 non-casino rewards programme members," the message from chief operating officer Paul Town said.

The data was accessed on 19 and 20 October. It included the names, email addresses, phone numbers, countries of residence and membership numbers of shoppers, the company said.

"Based on our investigation, we do not have evidence to date that the unauthorized third party has misused the data to cause harm to customers," Town said.

Town said the membership data of its casino rewards programme appeared to have been unaffected.

Marina Bay Sands was working with a cybersecurity firm to strengthen its systems, Town said.