Special forces have blockaded a gang of militants believed to have links to Al Qaeda in Russia's southern republic of Chechnya. Six gunmen were reportedly killed since the operation kicked off on Wednesday.

“Two of the six militants killed have been identified and the operation is continuing,” Chechen president Ramzan Kadyrov was quoted by Itar-Tass news agency as saying.

Kadyrov pointed out that, although the operation is being carried out in difficult terrain, state forces are “taking all possible measures not to let militants escape.”

Those killed were part of a group of around 30 militants hiding in the republic's mountainous region. Chechen president had earlier said that the group has connections with Al-Qaeda.

Three police officers have died and two were injured in the fighting, which is still going on.

The operation is part of a major crackdown on insurgents. It was launched soon after the lifting of a ten-year-long counter-terrorism regime in April 2009 in response to escalating violence.