Tajikistan detains nine over Russian concert massacre

Tajikistan has detained nine people this week suspected of having links to a mass shooting at a Russian concert hall and also to the militant Islamist group that claimed responsibility, a Tajik security source told Reuters.

Four suspected gunmen behind the deadliest attack in Russia in 20 years 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's state security committee detained nine people on Monday in the city of Vakhdat and the suspects are now in the capital, Dushanbe, the source said, without providing any further details.

At least 143 people were killed in the attack on the concert hall near Moscow last Friday.

Tajikistan, which is a member of a Russian-led security bloc and hosts a Russian military base, has also rounded up the families of the suspected gunmen so that Russian investigators can question them in Dushanbe, sources told Reuters this week.

The predominantly Muslim nation of 10 million bordering Afghanistan depends heavily on remittances from migrant labourers working in Russia. Its own economy was devastated by a civil war in the 1990s.

Islamic State has claimed responsibility for the concert hall attack and US 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", an assertion immediately dismissed by the United States as baseless propaganda.

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