Pro-Russian hackers reportedly crashed the Taiwan Stock Exchange website on Thursday, according to local media reports.

At 3 p.m. Taiwan time, the stock exchange said “a large number of foreign IPs launched invalid queries” on its network, resulting in “unstable service for a short period of time.”

The network returned to normal at 3:22 p.m. local time. The exchange added that the securities market and related businesses are “operating normally without any impact.” Taiwan’s markets close at 1:30 p.m. local time.

While the exchange did not specify the cause of the attack or the perpetrator of the attack, local media reported this was part of a distributed denial of service, or DDoS, attack on the Taiwanese government by a pro-Russian hacker group.

The attack reportedly targeted Taiwanese government and financial units, including airports and tax bureaus.

The Taipei Times reported information security company Radware said the attack was launched in retaliation for comments made by Taiwanese President William Lai.

On Sept. 1, Lai said in an interview that China’s claims on Taiwan are about changing the rules-based international order and achieving hegemony in the Western Pacific rather than territorial claims.

China views Taiwan as part of its territory and has not renounced the use of force against the island.

“It wants to achieve hegemony in the international area, in the Western Pacific — that is it’s real aim,” Lai said.

“If it is really about territorial integrity, why don’t they take back the land that was signed away and occupied by Russia in the Treaty of Aigun?” said Lai.

He added, “Now Russia is at its weakest. [The land in] the Treaty of Aigun, you [China] could have asked for it back, but you didn’t.”

The 1858 Treaty of Aigun was a treaty between the Qing dynasty — China’s last dynasty — and the Russian Empire that ceded around 600,000 square kilometers of land in Manchuria to Russia.

The Qing dynasty originally refused to ratify the treaty before confirming the cessation in the 1860 Convention of Peking in what China sees as an one of many “unequal treaties.”

In 1895, Taiwan was also ceded to Japan in another “unequal treaty,” known as the Treaty of Shimonoseki, before being placed under the control of the then Republic of China — Taiwan’s formal name — in 1945 after World War II.