Taliban forces attacked a large coalition airfield in eastern Afghanistan early Sunday morning, detonating three car bombs near the entrance of the base before sparking a two-hour gunbattle that claimed the lives of nine insurgents, three Afghan security guards and at least four civilians whose vehicle was caught in the crossfire, Afghan officials and witnesses said.

Disguised in coalition military uniforms, Taliban fighters attempted to enter the base after the initial suicide assault, which took place just before 6 am, but were repelled by firepower that included helicopter gunships, a coalition spokesman said. The confrontation wounded fewer than 10 coalition service members, though by late Sunday it remained unclear exactly how many or how severely. At least one member of the Afghan military was killed in the fighting.

The Taliban quickly took credit for the operation, claiming to have killed “tens” of foreign forces, though the insurgents routinely overstate the number of people killed by their attacks.

But the coordinated assault, which left the entry to the base strewn with bloody remains of the bombers, was a potent reminder of Taliban’s determination to continue the fight.

As coalition forces wind down the 11-year war, with combat troops already withdrawing, the attacks serve as a reminder that the Taliban are not going anywhere.

The base, known as Forward Operating Base Fenty, is primarily American, and is one of the larger airfields in eastern Afghanistan. Like other large coalition bases in the country, Fenty has been attacked before, including in February, when a suicide blast killed nine Afghans. The assaults have, in most cases, been repulsed before insurgents could fight their way inside the bases, and coalition casualties have been minimal, as appears to have been the case on Sunday.

But the Afghans who work or live near the base have not been so fortunate. Afghan officials said two of the civilians killed were doctors, whose car was riddled by gunfire about 50 yards from the base, said Haji Niamatullah Khan, district governor of Behsood. In addition, at least three private security guards who man the outer perimeter at the base were killed, he said.