Anti-Kremlin Russian activist Ildar Dadin has been killed while fighting for Ukraine in Kharkiv, according to his friend and Russian independent media.

Dadin was once jailed in Russia for repeatedly protesting the government of Russian President Vladimir Putin, in a series of peaceful street demonstrations. He was the first person to be convicted under a 2014 law that cracked down on public assembly and protests in Russia, according to Amnesty International.

He served two and a half years in prison and the article under which he was tried became known as “Dadin’s law.”

Dadin’s friend and former Russian lawmaker Ilya Ponomarev, who is living in exile, said Monday he was killed fighting in the Kharkiv region over the weekend.

“He had a keen sense of justice, so when he saw that there was an injustice – a war, an invasion, people were dying – he had to correct that injustice,” Ponomarev added.

The Freedom of Russia Legion confirmed Dadin was one of their soldiers but declined to comment on his condition and status on Monday due to ongoing combat operations.

Several independent Russian media outlets also reported Dadin’s death on Sunday.

More strikes on Ukraine overnight

Russia continued its attacks on Ukraine overnight, with Ukrainian authorities reporting four people killed and at least 25 injured in attacks on the Donetsk, Kharkiv, Kherson and Sumy regions.

Ukraine said it shot down 32 Russian drones and two missiles overnight and on Monday morning.

Ukraine also repelled a drone and missile attack on its capital on Monday. It marked the fourth Russian attack on Kyiv since the start of October, according to the head of the city’s military administration Serhiy Popko.

Meanwhile, the General Staff of Ukraine reported that it successfully struck an offshore oil terminal in Russian-occupied Crimea, near the city of Feodosia.

The Russia-appointed head of the Feodosia city administration, Igor Tkachenko, confirmed on Telegram that there was a fire at the oil terminal, which is the largest in Crimea. A state of emergency was declared in Feodosia due to the fire.

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