(CNN) -- A suicide bomber blew himself up at an entrance to Afghanistan's Bagram Airfield on Monday, an attack the Taliban called revenge for the burning of Qurans by U.S. troops there last month.
The blast at the base, north of Kabul, killed two civilians and wounded two others, Interior Ministry spokesman Sediq Seddiqi said.
A Taliban spokesman claimed 12 U.S. soldiers, including Special Forces members, and nine Afghans were killed in the blast, part of the group's "revenge campaign" for the Quran burning.
An Afghan official, however, said two personnel from the NATO-led mission in Afghanistan were wounded, and a spokesman for the mission, the International Security Assistance Force, said initial reports suggested no ISAF casualties.
The Taliban frequently exaggerate battlefield losses inflicted on ISAF personnel and have been accused of causing 75% of civilian casualties in the country.
News of the Qurans being burned sparked protests and attacks that have left at least 40 people dead, including four American soldiers, and hundreds more wounded.
U.S. officials have called the Quran burning an error by troops who were inadvertently given the Qurans and other religious materials to dispose of because they were thought to contain extremist inscriptions. U.S. President Barack Obama has apologized for the burning to his Afghan counterpart, Hamid Karzai.