Russian officials said on Thursday that gunmen traveling in several cars killed three police officers at a checkpoint after midnight, local time, on Thursday.

The Moscow-based National Anti-Terrorist Committee said the fighters had gone on to occupy a publishing house in the center of Grozny, capital of the North Caucasus federal republic of Chechnya. The committee said security and emergency personnel had surrounded the building.

Chechen leader Ramzan Kadyrov said on his Instagram account that the traffic police officers had died as they attempted to stop the cars carrying the gunmen.

"I ask residents in areas where operations are being carried out to abide by safety measures, and not to go out onto the streets without cause or to go near their windows," Kadyrov added. "All the talk about the city being under the control of military is absolutely false."

According to the state news agency RIA-Novosti, five police officers and others were injured in the clash. Meanwhile, Life News, a media outlet thought to have links to security services, said that some 15 people had earlier seized three vehicles in the village of Shalazhi and driven them to Grozny, some 50 kilometers (30 miles) away.

Kadyrov has been widely denounced for human rights abuses, including the killing of political opponents. He has also imposed Islamic restrictions such as the mandatory wearing of headscarves for women in public.

After a war between Moscow and separatists in the 1990s, the republic is still plagued by a Muslim insurgency and sporadic fighting in the mountains and southern regions. Five police officers were killed in a suicide bombing in Grozny in October this year.

rc/ksb (AP, AFP)