Moscow: Fighting between heavily-armed Islamists and police in the centre of Chechnya`s capital Grozny on Thursday left 19 dead and many injured, the second attack since October, officials said.
Militants barricaded themselves in a school and police cordonned off city streets, with the violence erupting just as President Vladimir Putin gave his annual address to the nation, vowing to end violence in Chechnya.
Chechnya`s head Ramzan Kadyrov said nine militants were killed after several hours of fighting in the city, with armed personnel carriers dispatched to residential areas and shooting in the streets.
The operation against the gunmen left 10 security officers dead and injured 28, Russia`s National Antiterrorism Committee said in a statement quoted by Russian news agencies.
It said police efforts -- which included the deployment of armoured personnel carriers in Grozny -- "liquidated" the group and "thwarted major acts of terror" but that some security actions were ongoing.
Putin had pledged to wipe out insurgency in the North Caucasus but simmering violence has continued in Chechnya and nearby regions, with a suicide blast rocking Chechnya in October.
Kadyrov said the militants were planning to stage an attack Friday but the plan fell through after traffic police stopped them in the early hours of Thursday.
It was unclear how many groups of militants were involved as they later stormed a building called the Press House in central Grozny as well as a school about a kilometre away.
"We have them surrounded in the school area," Kadyrov said on Echo of Moscow radio, adding that the gunmen were "very heavily armed", including with grenade launchers.
An AFP correspondent said a large area in the city centre was closed off by security forces, with automatic fire as well as larger calibre artillery audible several blocks away.
Authorities said gunmen inside the Press House -- a tall building that houses the media -- were eliminated, as it stood smouldering and gutted from fire.
Speaking in the Kremlin, Putin said he was certain that "local boys, local police, will suitably manage" to bring down the "latest raid by the terrorists."
A video posted by human rights activists of the Committee Against Torture showed two men with automatic weapons firing from a street corner several blocks away from the school.
North Caucasus Islamists, known as the Caucasus Emirate, took responsibility for the raid in a video posted on the website Kavkaz Center, saying it was revenge for "oppression of Muslim women."Thursday`s attack marks the first such raid in months by militants in Grozny -- which was ravaged by two wars between separatists and the Russian army over the past 20 years.
But it comes weeks after five policemen were killed and a dozen wounded in Grozny in October when they stopped a young suicide bomber from attacking a concert hall where thousands had gathered to mark a local holiday.
That attack shattered a period of relative calm in the region and sparked concerns of a new cycle of violence in the North Caucasus.
Despite claims by Kadyrov that Chechnya`s insurgency has been eradicated, "they have shown once again that they exist and continue doing what they were doing before," said Alexander Cherkasov of Memorial human rights centre.
"There is an insurgency in Chechnya, despite careful and total control over the republic`s residents, and perhaps because of it," he added.
Putin -- who launched the second Chechen war in 1999 when as prime minister he famously vowed to "wipe out (militants) in the outhouse" -- has staked his political career on a promise to crush the bloody insurgency in the Caucasus.
After the second Chechen war, a pro-Kremlin regime was installed in the republic, first headed by rebel-turned-Moscow-ally Akhmad Kadyrov and, following his slaying in a bombing in 2004, by his son Ramzan, a strongman who has ruthlessly put down opposition and whose regime has been accused of human rights violations.