Ten members of the pro-Russian Chechen military police force have been killed in an attack blamed on Chechen rebels in the south of the republic.

At least eight others were injured when their vehicle hit a radio controlled landmine in the southern Shatoi region.

Russian troops and the Chechen military police force are on high alert throughout Chechnya for the sixth anniversary of the rebels' capture of the capital, Grozny, during the first Chechen war.

Roadblocks around the capital have been strengthened for the anniversary, to prevent rebels infiltrating the city, and dozens of people are reported to have been detained.

The attack on the army truck was the bloodiest incident in the region since 18 policemen were killed by a bomb in Grozny in April.

The explosion was so strong that it threw the truck 15 meters (50 feet) away and flipped it over, one official said.

Chechen security chief Rudnik Dudayev told the Interfax news agency that all possible measures would be taken to find those who carried out the attack.

Extradition battle

In another development, Russia's chief prosecutor General Vladimir Ustinov is in Georgia to demand the extradition of a group of Chechen rebels detained over the weekend.

Tensions have been running high between the two countries, with Russia accusing Georgia of allowing raids into Chechnya by rebels, allegedly based in the Pankisi Gorge.

Russia must provide documentary evidence that these people committed crimes

Nugzar Gabrichidze Georgia's chief prosecutor

On Tuesday Georgia refused Mr Ustinov's request that the group of alleged rebels be handed over quickly, saying that it needs firm evidence of their criminal activity

"Russia must provide documentary evidence that these people committed crimes. Without that, they can't be extradited to Russia," Georgia's chief prosecutor Nugzar Gabrichidze said.

The Chechens were captured in Georgia on Sunday having taken remote mountain paths to cross over from Chechnya.