The men, aged 23 to 31 and mostly from the provincial city of Penza, were accused of planning attacks against the 2018 soccer World Cup and presidential election as part of an underground anarchist group called “the Network”. Other charges included drug dealing and weapons possession.

They had all denied the charges, and some said they were tortured in custody to produce confessions. Dozens of their supporters chanted “shame” in the military court in Penza as it handed down its ruling.

Asked about the case on a conference call, the Kremlin said President Vladimir Putin was aware of the case, but that it would not be appropriate for him to intervene in it.

“The president has repeatedly looked into this situation and repeatedly ordered everything to be checked thoroughly to make sure everything is in line with the law,” Kremlin spokesman Dmitry Peskov told reporters.

Opposition leader Alexei Navalny described the sentences as “horrific” in a post on Twitter.

“These very young people’s testimony about an imaginary terrorist organisation were beaten out using torture. Any minister in the Russian government is ten times more of a criminal and a threat to society than these guys,” he said. (Reporting by Tom Balmforth Additional reporting by Maria Tsvetkova Editing by Peter Graff)