A general view shows an attack on a military parade in Ahvaz, Iran, in this September 22, 2018 photo by ISNA. The photo is watermarked from source. ISNA/Iranian Students' News Agency/Social Media/via REUTERS

LONDON (Reuters) - Iran’s supreme leader, Ayatollah Ali Khamenei, said on Monday that the attackers who killed 25 people at a military parade were paid by Saudi Arabia and the United Arab Emirates, and Iran would “severely punish” those behind the attack.

“Based on reports, this cowardly act was done by people who the Americans come to help when they are trapped in Syria and Iraq, and are paid by Saudi Arabia and the UAE,” Khamenei was quoted as saying on his official website.