The Iranian senior diplomat offered condolences to the government and people of Russia, particularly the families of the victims.

He also said the Islamic Republic of Iran stands by Russia in this tragic incident.

At least 60 0eople have been killed and 145 wounded according to unofficial reports in the worst terror attack in Russia in years, as gunmen in combat fatigues opened fire and detonated explosives in a big concert hall in Moscow.

The attack, which left the concert hall in flames and its roof in a state of collapse, was one of the worst in Russia since the 2004 Beslan school siege in which more than 330 people, half of them children, were killed. The death toll appeared set to rise, according to unconfirmed reports.

Moscow Mayor Sergei Sobyanin said Friday’s raid was a “huge tragedy.” President Vladimir Putin was being given continuous updates about the situation, according to his spokesman Dmitry Peskov.