Taiwan’s government websites were most likely hit by Chinese “hacktivists” ahead of the US House of Representatives Speaker Nancy Pelosi‘s visit to the island nation, a cybersecurity research firm told Reuters.

The presidential office website was hit by a distributed denial of service (DDoS) attack and eventually began malfunctioning but was restored after 20 minutes, the president’s office said in a statement. A government portal and the country’s foreign ministry website were taken offline on Tuesday.

A DDoS attack is when millions of traffic requests are sent to a specific server in an attempt to overwhelm it and knock it offline. 

The foreign office said that the two websites had received a large number of requests from a “large number of IPs from China, Russia and other places”. Both had received 8.5 million traffic requests a minute. 

Johannes Ulrich, the Dean of  Research at the SANS Technology Institute, which specialises in cybersecurity education, told Reuters that the attacks were “uncoordinated, random, moral-lessattacks against websites that Chinese hacktivists use to get their message across.” However, he went on to say that while such attacks can occur continuously for days, these ‘hacktivists’ often lose interest within a week and they move on. 

“Many of the attacks are motivated by what is written in the Chinese press,” Ulrich told Reuters. 

Pelosi had announced her intention to visit Taiwan, which the Chinese government sees as a part of the mainland, setting off a diplomatic row. So far, China’s retaliation has included summoning the American ambassador to Beijing, naval exercises 12 miles off the coast of Taiwan and the halting of agricultural imports from the island nation. 

For three decades, ever since she unfurled a flag at Tiananmen Square in 1991 just two years after China’s brutal massacre of  pro-democracy protests by students, Pelosi has been an ardent supporter of Taiwan and has repeatedly made calls for the US to boycott China.