Militants have staged mass raids on government and police buildings in a provincial capital in Russia, leaving dozens dead and many more injured.
Authorities say most of the dead were rebels, but 12 police and 12 civilians also died in the assault on Nalchik in Kabardino-Balkaria province.
Officials say vehicles and troops have been deployed, the city has been sealed off and normality is returning.
Militants from nearby Chechnya are believed to be behind the attacks.
A pro-rebel website said a group known as the Caucasus Front had claimed the attack.
The raid is the latest in a series of disturbances that have been destabilising Russia's North Caucasus for more than a year.
Nalchik is about 100 km (60 miles) north-west of Beslan, where Chechen rebels took hundreds of hostages at a school in 2004, in an attack claimed by warlord Shamil Basayev.
'Find the bandits'
Dozens of men armed with rocket launchers are said to have been involved in the fighting which broke out early on Thursday.
The number of rebels killed is still unclear, with the latest estimates from local officials ranging from 20 to 50.
The BBC's Emma Simpson in Moscow says this appears to have been an all-out attack on Nalchik's law enforcement and security services.
A local Interior Ministry source told Itar-Tass that rebels launched a "carefully planned" simultaneous attack on police stations, security forces, military and drugs-control offices and the airport.
"All hell broke loose, and the impression was that there was shooting everywhere," a resident told Reuters news agency.
A school was also caught up in the running gun-battles, as black smoke billowed across the city.
Hostages were reportedly taken at one police station for a time.
President Vladimir Putin responded with an order for the city to be sealed off and for forces to shoot any armed resisters.
Correspondents say the streets were quiet by the evening, but police remained on guard.
"The city has been taken under firm control. Not one car, not one train, not one bus will go past without being closely checked," Deputy Interior Minister Alexander Chekalin said.
"Now our main task is to find the bandits in the city, including their wounded."
Website claim
The pro-rebel Kavkaz Center website said that a detachment of the Chechen-linked Kabardino-Balkaria jamaat, called Yarmuk, had entered Nalchik.
The use of the word jamaat indicates that it is made up of radical Islamic fighters.
Correspondents say violence in Kabardino-Balkaria has been steadily increasing.
Political changes and a harsh crackdown on alleged Islamic militants appear to have pushed the region to the verge of instability, the BBC's regional analyst Steven Eke says.
Our analyst says that after last year's Beslan massacre the government promised more money and support for the impoverished North Caucasus - but nothing has changed.
