A US military inquiry has concluded a suicide bomber infiltrated an American base in Mosul posing an Iraqi security officer and killed 22 people in a crowded dining tent last December.
The bomber was not employed at Forward Operating Base Marez in the northern Iraqi city and apparently entered without passing through a guarded perimeter gate, said Army Maj Gen David Rodriguez.
Maj Gen Rodriguez, who commands 10,000 US troops in the Mosul area, said the bomber was associated with the Islamic militant group Army of Ansar al-Sunna - one of the leading insurgent groups in Iraq.
The group said its suicide bomber, who it identified as Abu Omar al-Mosuli, entered the base during a changing of the guards.
"We were not able to determine exactly whether he was in the Iraqi security forces or just had stolen or acquired an Iraqi uniform for the Marez bombing," Mr Rodriguez said.
"We could never determine whether he was an Iraqi national or not," he added. The December 21st, 2004 bombing was the most lethal attack on a US military base in the war. It killed 22 people, including 14 US soldiers and four US contractors, and wounded about 60 when it ripped through a packed mess tent during lunch.