Russian President Vladimir Putin has called for a “deep and radical update” to Moscow’s migration policy. Putin’s remarks came after Tajiks living in Russia were detained for the deadly Moscow concert hall attack that killed at least 144 people on March 22.At least 12 people – including four gunmen – have been detained, most of whom are Tajiks who had lived and worked in Russia. Tajik officials have said there has been a rise in Tajiks leaving Russia since the attack at Crocus City Hall.Putin’s call for a revamp came at a meeting of Russia’s Interior Ministry which oversees the country’s national police force. Putin also told police chiefs that the attack was aimed at sowing discord, xenophobia and Islamophobia inside Russia.