Taliban rebels blasted into a prison using a suicide car bomb and guns late Friday, freeing as many as hundreds of militant prisoners and killing at least two guards, officials said.

The brazen attack under cover of darkness ripped through the front entrance of the main jail in the insurgency-hit southern city of Kandahar, Justice Minister Sarwar Danish told AFP.

But a Nato spokesman said the mass escape was an isolated incident that did not mean the militants were gaining strength in Afghanistan generally.

Afghan and Nato troops are searching for 350 militants who were among some 900 inmates to escape, officials said.

Fifteen guards died in the truck bomb and rocket attack in the southern city.

"I understand it was a very successful move for the Taleban, I'm not denying that, but we should not over-react and exaggerate in the results," Nato spokesman General Carlos Branco told the BBC.

"It's very soon to make an assessment and say that it was a strategic blow."

Hundreds of Taliban fighters are reported to have launched an offensive Monday into a district at Kandahar city's doorstep and are digging in anticipation of an assault on the city.

Taliban fighters have taken control of 10 villages in the Arghandab district of Kandahar province in Afghanistan, and have said they plan to march towards Kandahar city.

Mohammad Farooq, a government official in Arghandab, said on Monday that around 500 Taliban fighters moved into the area and took over the villages.

The very idea that anyone calling themselves "Taliban" could continue to organize and constitute any kind of threat let alone pull this off which will only strengthen their ranks, is utterly unacceptable this long after 9/11.

This is just one of so many messes Barack Obama will have to clean up after George Bush is gone. I don't envy him his task.

The spectacularly bold prison break attack by Taliban forces on a prison near Kandahar Friday evening included two truck bombs, assault rifles and rocket-propelled grenades and was thought to be exceptionally planned. After the Taliban blew up the walls of the prison killing fifteen guards, they freed close to 1,200 prisoners. Among which were estimated 350 Taliban members.

Is there a systemic change in the quality and effectiveness of Taliban ability to organize and direct violence? Or is this random noise? I would hazard that it is a change in effectiveness in the Taliban as we have clear proof of their ability to plan and execute a very complex operation in the form of this prison break.