MOSCOW (Reuters) -Russia has detained three more people suspected of involvement in last month's mass shooting at a concert hall near Moscow, the FSB security service was quoted as saying on Thursday.
A Russian citizen and two foreign citizens, all originally from Central Asia, were detained in Moscow, Yekaterinburg and Omsk, Interfax quoted an FSB statement as saying.
At least 144 people were killed in the March 22 attack on the Crocus City Hall, the deadliest in Russia for 20 years.
Militant group Islamic State claimed responsibility but Russia has said, without providing evidence, that it believes Ukraine was behind the massacre.
President Vladimir Putin said on Thursday that Russia "cannot be the target of terrorist attacks by Islamic fundamentalists" because it was a unique example of inter-faith harmony.
Putin did not mention Ukraine in his latest comments but he has previously said that Kyiv stood to gain from the attack and that the four suspected gunmen were heading for the Ukrainian border - where he said someone had prepared a "window" for them to cross over - at the time of their arrest in western Russia.
Ukraine has denied involvement and the United States, which had passed on an intelligence warning to Moscow about an impending attack by Islamist militants, has said Moscow's attempt to blame Kyiv is propaganda and nonsense.
Ten suspects, mostly from the Central Asian state of Tajikistan, have so far been formally placed in pre-trial custody.
According to the FSB, two of the three latest detainees transferred money for the purchase of firearms and vehicles used in the attack. It said the third was directly involved in recruiting accomplices and financing the perpetrators.
State media published an FSB video showing the three arrests, in which the suspects were seized on the street and bundled into unmarked vans.