Afghan troops backed by US air support launched a counter-offensive Tuesday to retake Kunduz, a day after Taliban terrorist group overran the strategic northern city in their biggest victory since being ousted from power in 2001.

Afghan troops backed by US air support launched a counter-offensive Tuesday to retake Kunduz, a day after Taliban terrorist group overran the strategic northern city in their biggest victory since being ousted from power in 2001.

The Taliban stormed Kunduz on Monday, capturing government buildings,
freeing hundreds of prisoners and raising their trademark white flag throughout
the city.

The stunning fall of the provincial capital, which has sent panicked residents fleeing, dealt a major blow to Afghanistan's NATO-trained security forces and spotlighted the insurgency's potential to expand beyond its rural strongholds.

Afghan security forces, who had retreated to the outlying airport after the fall, began a counter-strike on Tuesday backed by reinforcements.

"The operation to recapture Kunduz city began at 8:00 am (0330 GMT) today," the defense ministry said in a statement.

US forces also conducted an air strike in Kunduz province on Tuesday, a NATO statement said, without specifying the target.

The strike was carried out to "eliminate a threat to Afghan and coalition forces", the statement added.

Deputy Interior Minister Ayoub Salangi said earlier that security forces were ready to retake the city and vowed to investigate how the Taliban managed to seize a major urban centre for the first time in 14 years.

Marauding insurgents stormed the local jail, freeing hundreds of prisoners including some Taliban commanders, officials said.

Kunduz was swarming with Taliban fighters racing stolen police vehicles, who officials said overran the governor's compound and the police headquarters.

But the defense ministry on Tuesday claimed that the police headquarters and city prison had been retaken.