The militants were killed after being surrounded in a house in the Dagestani capital Makhachkala, the regional branch of the FSB said in a statement carried by official news agencies.

“Two of the dead have already been identified — they are Eldar Navruzov and Musa Davydov,” the FSB said, adding that both men had been wanted for carrying out attacks.

The ITAR-TASS state news agency reported both men had belonged to a militant group led by Magomedali Vagabov, the husband of Maryam Sharipova, a suicide bomber who blew herself up in the Moscow metro in March.

Sharipova and another woman, both of them from Dagestan, carried out a pair of coordinated suicide bombings on March 29 that killed 40 people in the Russian capital.

Dagestan, a predominantly Muslim region of Russia located between war-torn Chechnya and the Caspian Sea, has been troubled by a violent Islamist insurgency that has repeatedly attacked official targets.