At least five Macau government websites were knocked offline by suspected foreign hackers for almost an hour earlier this week, several Chinese media outlets reported, citing local security officials.

A distributed denial-of-service attack (DDoS) affected, among others, the websites of Macau’s security service, police force, fire and rescue services, and the academy for public security forces.

The densely populated Macau is a “special administrative region” on the south coast of China. Local police have launched a criminal investigation into the incidents to trace the source of the criminal activity.

The attack occurred on Wednesday evening and likely originated “from overseas,” according to local officials.

Following the incident, Macau’s authorities carried out an emergency response “in collaboration with telecommunication operators to promptly restore regular services,” said the region’s Secretary for Security, Wong Sio Chak.

The country’s security forces also instructed Macau Telecom, which provides the services to block DDoS attacks, to investigate the incident and submit a report and improvement plan to prevent similar attacks in the future.

It is not clear what hacker group was behind the incident or what their motives were.

Local media claimed that the latest attacks followed a surge in cyber activities in the region. According to a recent report, the number of cyberattacks targeting Macau’s critical infrastructure last year has more than tripled since 2020.