He said that the bomber was suspected of involvement in several terrorist crimes.

The blast happened close to the capital's concert hall, forcing 800 people to be evacuated.

Among those killed by the blast were a Chechen public security deputy chief, the head of coordination at the Chechen Interior ministry and several other officials.

The Chechen president Ramzan Kadyrov had been expected to attend the concert, but was late.

Attacks have increased after Kadyrov vowed to press on with a counter-terrorist operation to wipe out the remaining militants in the region.

Kadyrov has also ordered former militant leaders who have laid down their weapons to join the hunt for bandits hiding in the mountains.

Magomed Khambiev, former Defense Minister of the recently-surrendered Ichkerian government [the Turkish name of Chechnya used by the self-proclaimed government-in-exile] and former field commander Shaa Turlayev have personally received the orders. At the same time Khambiev has been appointed to the position of Kadyrov’s out-of-staff assistant and Turlayev will now be an adviser to the President.

Since the middle of May, special forces in Chechnya and Ingushetia have been holding a joint counter-terrorist operation on the border, targeting the militants' bases.