Karzai, government ministers and other dignitaries fled the scene after gunfire sounded at the military parade to mark the 16th anniversary of the fall of the country's Soviet-backed communist regime.
Western media reported that Taliban militants had claimed responsibility for the assault while a source in the Afghan Defense Ministry told RIA Novosti that the Islamic Party of Afghanistan led by Gulbaddin Hekmatiyar said it had carried out the attack.
Karzai was unhurt in the assault and later appeared on national television, saying that several suspects had been arrested and that a thorough investigation into the attack would be carried out.
Karzai has led Afghanistan since after a U.S.-led force overthrew the Taliban regime in 2001.
