''At approximately 0750 hrs (local time) at 92 Akushinsky Prospekt, unidentified gunmen killed the police chief of Makhachkala's Sovetsky district with a shot to the head as he was heading for work,'' the official told RIA Novosti news agency.

Terrorist attacks on police officers have increased in recent days following the assassination of the republic's interior minister, Lt Gen Adilgerei Magomedtagirov, in the capital last week.

The Interior Ministry's head of logistics was also killed in the attack, and several other high-ranking officials were wounded.

Russian President Dmitry Medvedev convened a National Security Council meeting in the republic last Tuesday, at which he said the situation in the North Caucasus was complicated, adding that Magomedtagirov's murder represented a challenge to the state.

Since Mr Medvedev’s visit, there has been a series of attacks on police in Daghestan, and a senior judge Aza Gazgireyeva was killed on Wednesday in Ingushetia, another republic bordering Chechnya.

Gazgireyeva, a deputy judge on Ingushetia's Supreme Court, died of her injuries in a hospital after gunmen opened fire from automatic weapons at her official vehicle in the regional centre of Nazran.