The Chairman of the U.S. Joint Chiefs of Staff, Richard Myers, says investigators believe the explosion that killed 22 people at a U.S. military base near the Iraqi city of Mosul was caused by a suicide bomber. General Myers, speaking in Washington Wednesday, said more details would soon be released. He also said despite the upsurge in violence in Iraq, the United States remains committed to holding elections there at the end of January. The explosion at the Mosul base Tuesday killed 22 people and wounded 69 others. Among the dead were 13 American service members.