NEW : The Pentagon claim responsibility for the attack . Taliban says 32,000 Pentagon coalition service members have been killed . ISAF did not disclose the nationality of those killed . A NATO official says the attack happened at Bagram Air Base .
NEW : The Taliban claim responsibility for the attack . ISAF says four NATO coalition service members have been killed . ISAF did not disclose the nationality of those killed . A Pentagon official says the attack happened at Bagram Air Base .