Russian President Dmitry Medvedev has made a surprise visit to the restive North Caucasus republic of Dagestan to discuss recent terrorist attacks emanating from the region, news agencies reported on Thursday.

"We must broaden the range of counter terrorism measures and make them more efficient and tougher. (Terrorists) must be punished," said Medvedev as quoted by the Interfax news agency.

The president, who arrived at the regional capital of Makhachkala by helicopter, will chair a meeting of heads of North Caucasian republics and territorial units of the Federal Security Service (FSB) and the Interior Ministry.

The visit by Medvedev, accompanied by FSB chief Alexander Bortnikov and Interior Minister Rashid Nurgaliyev, came a day after 12 people, including nine police officers, were killed in two blasts in the Dagestani town of Kizlyar.

Bortnikov and Nurgaliyev briefed the Russian head of state on the situation in the North Caucasian republic after the bomb attacks.

On Monday, two female suicide bombers killed 39 in attacks on the Moscow subway system, which the authorities have linked to militants from the North Caucasus.

Earlier on Thursday, the Investigative Committee of Russian Prosecutor General's Office announced the establishment of a permanent terrorism investigative group in Dagestan combining staff from the Investigative Committee, the Interior Ministry and FSB.

Russia's North Caucasus republics, particularly Chechnya, Dagestan and Ingushetia, have been plagued by violence, particularly against law enforcement officers, which local rebels see as representing the Russian authorities.