Kabul , Afghanistan ( CNN ) -- Nearly a dozen insurgents and a U.S. contractor were killed when a group launched an early morning attack on Bagram Air Base in Afghanistan on Wednesday , officials said . Nine service members were wounded and a building received minor damages during the attack , which included rockets , small arms and grenades . Four of the slain insurgents were `` intended suicide bombers , '' the military said . U.S. Army spokesman Lt. Col. Clarence Count Jr. said the insurgents failed `` to breach the perimeter '' and were `` unable to detonate their suicide vests . '' `` The quick defensive reaction by the Bagram security forces likely saved a lot of lives , '' he said . The Taliban claimed responsibility for the attack . Zabiullah Mujahid , a Taliban spokesman , told CNN that 20 armed men wearing suicide vests stormed the base around 4 a.m. ( 7:30 p.m. Tuesday ET ) , with four them detonating at the entrances to allow the other men to move in . Mujahid said that a `` major firefight '' took place inside the base . Army Specialist Christina Dion , a spokeswoman who both lives and works on the base , said personnel were ordered to bunkers when the base came under attack and were allowed to return to their huts and tents about 90 minutes later . `` We 're always prepared to deal with attacks on our base , '' Counts said . `` The response this morning was immediate . '' The fighting eventually tapered off about 7:30 a.m. local time , said NATO spokesman Lt. Col Todd Breasseale . Another Bagram spokeswoman , Maj. Virginia McCabe , could not say if flights into and out of the air base had been stopped and said that authorities are investigating how the incident started . `` Established security procedures are in place , '' she said , adding that personnel with `` mission-essential '' responsibilities were continuing to work . Bagram is a heavily fortified base , its perimeter guarded by high fences and thick , concrete walls . Dion said she did n't believe anyone could have made their way into the main portion of the base . Taliban fighters have lobbed rockets into the base in previous attacks . CNN 's Adam Levine and Paula Hancocks contributed to this report .
Nearly 100 Taliban , 1 U.S. were killed in attack on Bagram Air Base . The Taliban said 20 armed men in suicide vests stormed the base . Taliban official says insurgents did n't breach base . Militants have lobbed grenades into base in previous attacks .