A police officer has been shot dead in the Chechen capital of Grozny, a police source told RIA Novosti on Friday. The off-duty police officer was attacked by two unknown assailants in Grozny`s Oktyabrsky district on Thursday, the source said. Russia`s North Caucasus has seen a rise in violence in recent months, despite the Kremlin officially ending its 10-year counter-terrorism operation in Chechnya.