STEPHEN McGRATH, ANDREEA ALEXANDRU BUCHAREST, Romania — Romanian President Nicusor Dan on Tuesday called an alleged Russian sabotage plot last month a “grave violation” of the NATO member’s sovereignty and security, at a time when many fear Moscow’s war in neighboring Ukraine risks spreading beyond its borders.

Dan’s remarks came a day after the Romanian Intelligence Service said it identified a Russia-coordinated “sabotage network” linked to the fire in central Brasov County on Sept. 14. The fire damaged the premises of several commercial entities, authorities said.

Video footage released by the intelligence service showed a person climbing the ladder of a building’s fire escape, followed by brief flashes and flames engulfing a building. Two people were then seen cycling away from the scene.

“I condemn, in the strongest possible terms, any involvement by the Russian Federation in acts of sabotage on Romanian territory,” Dan said in a post on Facebook. “Such actions are unacceptable and constitute a grave violation of our country’s sovereignty and security.”On Monday, Romania’s anti-organized crime agency, DIICOT, said that three foreign nationals — two Belarusians and one Ukrainian, all residing in European Union countries — were being investigated in connection with the fire in Brasov.

Two suspects were arrested in Germany while “preparing to commit similar acts,” and a European arrest warrant was issued Monday for another defendant located in Poland, the agency said. The agency added the authorities are seeking to extradite the three suspects to Romania.

Dan said the incident was part of a broader “hybrid war” conducted by Moscow that aims to weaken European democracies. He alleged tactics include interfering with elections , conducting disinformation campaigns, cyberattacks and acts of sabotage.

“This hybrid war has been ongoing for years, taking various forms, all with the same objective: to weaken European states from within and to erode the solidarity among them,” he said.

Russia did not immediately comment on the allegations but has repeatedly denied conducting sabotage plots against European countries.

The Romanian Intelligence Service said data obtained indicated the “network’s missions were not limited to Romania” and alleged Russia had “assigned it a wide range of targets across the region.”It said the targets included state-owned and private arms manufacturing facilities and other sites of military and industrial interest.

“Investigations conducted this year have uncovered other attempts targeting sites in Romania, including international military facilities or locations used for the training of Ukrainian armed forces,” the intelligence service said.

Romania’s Interior Ministry also said Monday that the suspects’ alleged activities “align with the patterns observed in other cases already investigated and attributed” to Russia.

Romanian Prime Minister Luca Niculescu on Tuesday also condemned the alleged Russian plot and said the authorities dismantled a Russian sabotage network targeting the defense industry.

“I consider such attacks unacceptable,” he said. “We will not be deterred in our commitment to ensure the security of Romanian citizens and Romania.”In his statement, President Dan also blamed Russia for a spate of attacks in recent weeks on civilian maritime transport in the Black Sea , which has left at least 3 people dead and has raised fears of an escalation in Russia’s war against Ukraine.

“Let us be clear: These are not isolated, unrelated incidents; rather, they are part of a premeditated and coordinated campaign aimed at sowing division within our societies and undermining the commitment of European states to their own security and to collective defense,” he said. McGrath reported from Leamington Spa, England.