Ukraine’s SBU security service says it has arrested a local resident suspected of planning a Russian-ordered cyberattack on Ukrainian state institutions.

“The attack targeted central and local governments, and the aim was to block the operation of information and critical infrastructure facilities,” an SBU statement said.

STB operatives ”established that the special services of the Russian Federation acted through a resident of [the southeastern Ukrainian city of] Zaporizhzhya,” the statement said.

The SBU said the hacker was meant to send a disguised file containing spyware to Ukrainian officials.

Russia’s Federal Security Service (FSB) did not immediately respond to a request for comment.

Last month, the SBU said it had prevented a large cyberattack by Russian hackers aimed at classified government data.

Ukraine has previously accused Russia of orchestrating cyberattacks as part of a “hybrid war” against Ukraine. Russia denies this.

Relations between Ukraine and Russia have been tense since Russia’s annexation of Crimea from Ukraine in 2014 and its involvement in a conflict in Ukraine’s east.

Kyiv, its Western allies and NATO have accused Russia of a provocative troop buildup on Ukraine’s eastern border and in Crimea.

With reporting by Reuters