Sept. 25 (UPI) -- Iranian authorities have arrested nearly two dozen people and seized materials related to the deadly shooting at a military parade last weekend, officials said.
Iranian officials said men dressed in military uniforms killed at least 29 people and injured 70 Saturday at a parade to commemorate the end of the Iran-Iraq war. Tehran's intelligence ministry identified five men it said were linked to the attack and Arab reactionary countries. Seventeen others were also arrested.
"Foreign sponsors and supporters of this terrorist act have also been identified," Iranian authorities said in a statement.
Iran pledged revenge for the attacks Monday in a thinly-veiled warning to the United States and allies Saudi Arabia and Israel.
An armed militia called al-Ahvaziya claimed responsibility for the attack. The Islamic State also claimed complicity.
Iranian President Hassan Rouhani, who's in New York City this week for the United Nations General Assembly, promised a "crushing response" to the attack. Foreign Minister Javad Zarif blamed "regional terror sponsors" and said Tehran will hold "their U.S. masters accountable."
Thousands have gathered in Ahvaz this week for funerals for the victims.