By Stephen Mulvey BBC News Online

The Chechens who shot down a Russian helicopter in Ingushetia in September were until recently sheltering in Georgia's Pankisi gorge.

It seems they've left and are already in Russian territory - let Russia deal with them

Georgian deputy Security Minister

They are precisely the kind of men Russia accuses Georgia of protecting by allowing them to rest on Georgian territory, and then launch attacks on Russian forces in Chechnya.

However, it is unclear whether this time the Chechens crossed the border voluntarily, or whether they were driven out by Georgian soldiers.

What is clear is that the rebels have less and less room for manoeuvre.

Guerrilla tactics

Russian threats to cross the border and liquidate the rebels on Georgian territory force Georgia to make serious efforts to get them out.

Ruslan Gelayev: Warlord on the move

"We purposefully get rid of uninvited armed guests who have arrived from Russia," said Georgian deputy Security Minister Lasha Natslishvili on Thursday.

"We want them to leave and it seems they've left and are already in Russian territory. Let Russia deal with them."

Russia has complained that the Georgian effort to sweep the gorge for rebels was ineffective - because instead of killing or arresting the Chechens, they were allowed to escape.

Georgia has responded that they were only there in the first place because they were driven out of Chechnya - not killed - by the Russians.

For the last two years the rebels have avoided pitched battles with Russian forces, preferring guerrilla tactics - exploding mines and car-bombs or shooting down helicopters.

Winter troubles

It's widely assumed that they no longer have the strength to risk losing large numbers of men and equipment in head-on confrontations with the enemy.

Convoys get air cover, but helicopters are vulnerable

The leader of the rebel group involved in the battle on Thursday, is reported to be Abdul Malik, one of the lieutenants of the warlord Ruslan Gelayev.

The Kremlin says they number between 100 and 150, and that they crossed into Ingushetia from Georgia in small groups.

Another group which crossed into neighbouring North Ossetia was reportedly wiped out by Russian forces before it could link up with the others.

Among the dead are reportedly Arabs, a Turk and a Georgian.

The winter has always been a difficult time of year for the Chechen rebels, and not just because of the low temperatures at high altitude.

Snow makes the borders difficult to cross, and cover from the tree canopy disappears.

There is now a sense that the rebels can run, but they cannot hide.

On the other hand, the rebels have often been at their most resourceful when under pressure - for example the daring hostage-taking raid on the Russian town of Budyonnovsk in 1995.

They may be in trouble but they are still a force to be reckoned with.