Russia claims Ukraine was involved in concert hall terror attack

Close aides of Russian President Vladimir Putin are backing his assertion that Ukraine could have been involved in the terrorist attack near Moscow last week. Ukraine denies the allegations.

The mass shooting on Friday has left at least 139 people dead. Russian authorities have indicted four people.

Putin has noted that the attack was carried out by Islamic extremists, but he has also indicated that Ukraine may have been involved.

On Tuesday, Russian Security Council Secretary Nikolai Patrushev said "a lot indicates" that Ukraine was behind the attack.

Alexander Bortnikov, the director of Russia's Federal Security Service, told reporters that the United States and Britain are also suspected of having been involved.

Observers say that Moscow may be further strengthening its claims to justify its invasion of Ukraine.

President Volodymyr Zelenskyy has flatly denied that Ukraine was involved in the attack, and he has strongly refuted Russia's allegations.

Meanwhile, a group of UN experts says some of the suspects detained in connection with the attack "appear to have been grossly mistreated in custody."

Mariana Katzarova, the Special Rapporteur on the situation of human rights in the Russian Federation, is one of the experts. The team issued a report on Monday.

It said, "Russia must investigate all credible allegations of torture or cruel, inhuman and degrading treatment or punishment."

It added, "Torture compromises fair trials and thwarts justice for victims of terrorism."

An independent Russian media outlet has reported that video clips and photos shot at a court and elsewhere show that the detainees were severely beaten.

They say that one of the detainees' ears may have been cut off and that the suspects may have been electrocuted.

On Monday, Russian presidential spokesperson Dmitry Peskov declined to answer a question posed by a reporter about whether the detainees had been tortured.