GHAZNI: Explosions and sporadic gunfire rocked the outskirts of Ghazni on Tuesday after the Taliban attempted to storm the southeastern city, as the insurgents tighten their grip across Afghanistan following their lightning capture of another provincial capital.

Afghan forces repelled the brazen assault on Monday, but it rang security alarm bells as the largely rural insurgency threatens large cities for the first time in 14 years of war.

The violence, which emptied the streets of Ghazni, follows the Taliban's three-day occupation of northern Kunduz city and other attempts by militants to overrun provincial capitals in the north.

Around 2,000 insurgents attacked Ghazni from several directions on Monday, coming as close as five kilometres to the city, deputy provincial governor Mohammad Ali Ahmadi said.

“But they were quickly pushed back by Afghan forces,” Ahmadi told AFP.

“Military reinforcements have arrived from neighbouring provinces to secure the city.“ The fighting left the streets of Ghazni largely deserted for a second day as many panicked residents tried to flee towards the capital Kabul.

In Kunduz, meanwhile, the Taliban admitted on Tuesday that they had tactically retreated from the main intersections, markets and other government buildings.

Afghan soldiers, backed by NATO special forces, are still combing the city to flush out pockets of insurgents hiding in civilian homes.

The fall of Kunduz on September 28 was a stinging blow to Western-trained Afghan forces, who have largely been fighting on their own since the end of NATO's combat mission in December.

As fighting spreads in neighbouring provinces such as Badakhshan and Takhar, concerns are mounting that the city's seizure was merely the opening gambit in a new, bolder strategy to tighten the insurgency's grip across Afghanistan.

It raises the prospect of a domino effect of big cities falling into the hands of the Taliban for the first time since they were toppled from power in a 2001 US-led invasion.

The militants last week attempted to overrun Maimana, the capital of Faryab province, but were pushed back by Afghan forces with the aid of pro-government militias.

Guerilla war

“With this kind of guerrilla fighting focused around big cities, the Taliban are exerting enormous pressure on overstretched Afghan forces,“ Kabul-based military analyst Atiqullah Amarkhil told AFP.

“The Taliban know they can't control a city for long, but capturing one, even momentarily, is a huge propaganda win.“

The NATO coalition said Tuesday that US and Afghan forces carried out one of their largest joint operations in southern Kandahar province, dismantling a major Al-Qaeda sanctuary in the Taliban's historic heartland.

The news came after a series of devastating setbacks.

NATO forces are under pressure after a US air strike on October 3 pummelled a hospital in Kunduz run by Doctors Without Borders (MSF), killing at least 12 staff and 10 patients.

The medical charity shut down the trauma centre, branding the incident a “war crime” and demanding an international investigation into the incident, which sparked an avalanche of global condemnation.

A Taliban suicide bomber on Sunday targeted a British military convoy in Kabul in a rush-hour attack that wounded at least three civilians including a child.

NATO also confirmed that two Americans, two Britons and a Frenchman were killed in a helicopter crash in Kabul Sunday, though the coalition ruled out any insurgent activity behind the incident.

And on Monday, unidentified gunmen on a motorcycle shot dead a woman working as a rights defender with the UN in Kandahar. Officials are investigating the motive behind the killing.