YEREVAN, MARCH 29, ARMENPRESS. Tajikistan has detained nine people this week suspected of having links to a mass shooting at Crocus City concert hall on March 22 and also to the militant Islamist group that claimed responsibility, a Tajik security source told Reuters.

Tajikistan's state security committee detained nine people on March 25 in the city of Vakhdat and the suspects are now in the capital, Dushanbe, the source said, without providing any further details.

Four suspected gunmen behind the attack, that killed at least 143 people, are Tajik citizens. They have been arrested along with seven other suspects, some of whom also come from the ex-Soviet Central Asian nation.

Tajikistan has also rounded up the families of the suspected gunmen so that Russian investigators can question them in Dushanbe, sources told Reuters this week.

Islamic State has claimed responsibility for the concert hall attack and U.S. officials say they have intelligence showing it was carried out by the network's Afghan branch, Islamic State Khorasan (ISIS-K).

Russian investigators said on Thursday they had found proof that the concert hall gunmen were linked to "Ukrainian nationalists."

Kyiv has strongly denied any involvement in the concert hall attack.