Britain on February 21 sanctioned six individuals running the Russian Arctic prison where the death of Kremlin opponent Aleksei Navalny was announced on February 16. Those sanctioned -- the camp's head, Colonel Vadim Kalinin, and his five deputies -- will be banned from Britain and have their assets frozen, the Foreign Office said. "Navalny suffered from being denied medical treatment, as well as having to walk in [minus] 32 [degree Celsius] weather while being held in the prison," the statement said. "Those responsible for Navalny’s brutal treatment should be under no illusion -- we will hold them accountable," Foreign Secretary David Cameron said.