BERLIN/MILAN: A Ukrainian man was arrested at a holiday bungalow in Italy on Thursday on suspicion of coordinating attacks on three Nord Stream gas pipelines in 2022, marking a breakthrough in an episode that sharpened tensions between Russia and the West.

Described by both Moscow and the West as an act of sabotage, the explosions largely severed Russian gas supplies to Europe, prompting a major escalation in the Ukraine conflict and squeezing energy supplies on the continent. No one has taken responsibility for the blasts and Ukraine has denied any role. The arrest comes just as Kyiv is engaged in fraught diplomatic discussions with the United States over how to end the war in Ukraine without giving away major concessions and swathes of its own territory to Russia.

“Politically we are firmly on Ukraine’s side and will continue to do so,” said Justice Minister Stefanie Hubig when asked if the arrest would affect Berlin’s ties to Kyiv. “What is important for me is that Germany is a country of laws and crimes in our jurisdiction are fully investigated.”

An official in the Ukrainian president’s office said he could not comment as it was not clear who had been arrested. The official reiterated Ukraine’s denial of any role in the blasts.