Ukraine will establish a “IT army” to combat Russian cyber breaches, Vice Prime Minister Mykhailo Fedorov said on Saturday.

According to Reuters, Ukraine has formed a hacker underground to assist secure key infrastructure and undertake cyber surveillance missions against Russian forces.

“We are forming an IT army,” Fedorov stated in a Tweet that linked to a Telegram channel that published a list of significant Russian websites.

“Everyone will be assigned assignments. We are still fighting on the cyber battlefield. The first assignment is on the channel for cyber experts.”

The Telegram channel listed the websites of 31 major Russian businesses and state organizations including energy giant Gazprom, Russia’s second-largest oil producer Lukoil, three banks and a handful of government websites.

Kremlin.ru, the official website of the Kremlin and the office of Russian President Vladimir Putin, was taken offline on Saturday in an apparent distributed denial of service (DDoS) attack.

Malicious data-wiping software was discovered circulating in Ukraine last week, hitting hundreds of computers, according to researchers at the cybersecurity firm ESET.

Suspicion fell on Russia, which has repeatedly been accused of hacks against Ukraine and other countries. The victims included government agencies and a financial institution.

Britain and the United States said Russian military hackers were behind a spate of DDoS attacks last week that briefly knocked Ukrainian banking and government websites offline before the Russian invasion.

Russia has denied the allegations.