The International Security Assistance Force in Afghanistan says its paratroopers and Afghan National Army soldiers have advanced deep into the Taliban's heartland in Helmand province.
A NATO statement Monday says the excursion marks the first time Afghan and ISAF forces "have driven this deep" into the area.
NATO said as the Afghan Army arrived in large numbers, the insurgents were not able to sustain the fight and retreated.
Also, several suspects have been arrested after a suicide attack killed six American troops when an explosives-packed minibus blew up at the entrance of a joint NATO-Afghan base in southern Afghanistan, officials said Monday.
The assault came days ahead of a major White House review of its Afghan strategy following President Barack Obama's decision last year to send 30,000 American reinforcements in a bid to reverse gains by the Taliban since they were ousted from power in the 2001 U.S.-led invasion.
Some information for this report was provided by AP.