Rebel gunmen have shot their way into the heavily fortified Chechen capital, Grozny, in a night-time attack which left as many as 16 people dead.
Arriving at 01:00 (22:00 GMT Wednesday) in cars, they fired on a traffic police checkpoint before attacking a media building and a school.
An Islamist group said it had launched a suicide attack to avenge attacks by security forces on Muslim women.
Chechnya's Moscow-backed president said the situation was under control.
Ramzan Kadyrov said none of the attackers had escaped.
The controversial Chechen strongman has suppressed rebel activity in Chechnya since Russia ousted the separatist government there at the beginning of the century.
The attack was a rare breach of the heavy security which surrounds Grozny.
Russian President Vladimir Putin said from Moscow he was confident Chechen security forces could handle the militants by themselves.
This is the most serious violence in Grozny for some time and will be another worry for President Putin, amid a serious downturn in the Russian economy, the BBC's Sarah Rainsford reports from Moscow.
Mr Putin prides himself on bringing stability to Chechnya after two bloody, separatist wars there since the break-up of the Soviet Union, our correspondent adds.
Three traffic policemen were killed as they tried to stop the gunmen's cars, Mr Kadyrov said.
Nine militants died in the subsequent fighting, the Chechen leader said.
According to the Russian government, a further four people died and 21 were injured during the fighting.
Inhabitants of the city woke to the sight of smoke rising from the gutted shell of the publishing house, where both Chechen and federal Russian media had offices.
Covered stalls at a market were also burned in the fighting.
There were no reports of any children being inside the school when the rebels seized it.
Mobile phone videos posted during the night attested to the ferocity of the fighting.
An Associated Press reporter saw the publishing house in flames and heard the continuing sound of gunfire before dawn.
The same reporter also saw the body of someone in civilian clothing in the street near the building.
"Not one bandit managed to get out," Mr Kadyrov later announced. "I directly ran the operation myself."
In a grainy video posted on YouTube, a gunman said he and a group of others had attacked the city in a "revenge operation" to avenge Muslim women harassed by the security forces.
He said the attack had been carried out on the instructions of Chechen rebel figure Aslan Byutukayev, an associate of Doku Umarov, the rebel leader believed to have been killed earlier this year.
The attack on Grozny came hours before President Putin gave his annual state of the nation address at the Kremlin.
Dmitry Trenin, who heads the Carnegie Moscow Center, wrote in a Twitter post that the night attack in Grozny looked "senseless except as an attempt to embarrass Putin hours before his annual address".