South Korea’s Ministry of National Defense website went down Tuesday afternoon after suffering potential cyberattacks.

The Defense Ministry said Wednesday its website was targeted by a suspected distributed denial-of-service attack, which is when service is disrupted by a flood of traffic.

The website of the Joint Chiefs of Staff was temporarily inaccessible Wednesday morning, with the Cyber Operations Command investigating whether attacks by foreign sources are responsible.

While the JCS website has recovered normal operations, the Defense Ministry website was still experiencing glitches at the time of writing.

According to the Defense Ministry, cyberattacks targeting its website are rare, although the Cyber Operations Command says hacking attempts by North Korea have increased over the past five years.

The Cyber Operations Command reported to the National Assembly last week that it was wary of possible cyberattacks from North Korea, aided by Russia, against the South Korean military and affiliated institutions.

The Korea Internet and Security Agency in charge of cybersecurity warned earlier this month of growing threats of cyberattacks by Russia-backed North Korean hackers amid Pyongyang’s troop dispatch for the war in Ukraine.