Russian President Vladimir Putin has threatened to punish Russian citizens who fight for terrorist groups abroad by stripping them of their passports.
Speaking in an interview with Russia's Mir 24 television channel on Tuesday, Putin said that officials would find a way to bypass the Russian Constitution, which forbids the government from depriving their subjects of Russian citizenship.
Bureaucrats could instead target dual-nationals or those who acquired Russian citizenship during their adult lives, the president said.
"In accordance with the Russian Constitution, we can not deprive anyone of citizenship. But we can cancel the relevant decisions which served as the basis for them to obtain Russian citizenship," Putin said.
"We will consult with our lawyers, and I think a decision on this will be taken in the very near future," he said.
Putin's words follow news that the man believed to have carried out a terrorist attack in St. Petersburg last week, 22-year old Akbarzhon Dzhalilov, was a Kyrgyz-born Russian citizen.
During the interview, Putin said that an estimated 4,000 Russian citizens were currently fighting alongside the Islamic State terrorist group in Iraq and Syria.