Two days after Boston bomber Dzhokhar Tsarnaev was sentenced to death by a federal grand jury, Ramzan Kadyrov, head of the Chechen Republic, accused U.S. intelligence services of framing Tsarnaev to hide their own involvement in the bombing. Kadyrov, who came to power in 2007 following a violent armed struggle, made the comments on his Instagram account on Sunday.

“Dzhokhar Tsarnaev was sentenced to death. This news does not surprise anyone. U.S. intelligence agencies, who were accused of involvement in the Boston tragedy, had to find a victim. Tsarnaev was handed to them as a victim,” Kadyrov wrote. “If they (the Tsarnaev brothers) actually carried out that attack, I don’t believe the U.S. special intelligence services didn’t know about it.”

Several conspiracy theories have formed since the attack during the 2013 Boston Marathon, which killed three people and injured several others, ranging from beliefs that the media knew of the attacks beforehand to claims that the Tsarnaev brothers (Tamerlan and Dzokhar) were CIA double agents.

Kadyrov, who has been accused of governing Chechnya like a “medieval tyrant,” is considered one of the most powerful figures in Russia. It is believed that since he replaced Alu Alkhanov as head of the republic, Kadyrov has been given free rein by Russian President Vladimir Putin to govern the region as he wishes.

“Who can guarantee that after sending Tsarnaev to death, he won’t be found innocent? This often happens in the United States. He was nine years old when he arrived at the United States, and the America he trusted now made ​​him a terrorist,” Kadyrov wrote.

Tsarnaev, an ethnic Chechen, was sentenced to death on Friday for his role in the bombing. However, it is likely to take decades for a lengthy appeals process to wind down before Tsarnaev is executed. Some analysts have expressed fears that Tsarnaev’s execution could paint him as a martyr and inspire more attacks.

“Tsarnaev is a criminal and a terrorist responsible for one of the most reprehensible attacks in Boston's history … I do fear that the death penalty could cause some Islamic terrorist groups to paint him as a martyr,” Nicholas Burns, a professor of diplomacy and international relations at Harvard's Kennedy School of Government, told the Associated Press, arguing in favor of a life sentence.