WASHINGTON, Sept. 23 (Xinhua) -- U.S. Secretary of State Mike Pompeo on Sunday rejected Tehran's accusations that Washington and its allies should be held accountable for a deadly parade attack in Iran.

Following the terror attack on a military parade in Iran's southwestern city of Ahvaz on Saturday, Iran's Supreme Leader Ayatollah Ali Khamenei said the attack "is the extension of the plots by the U.S. allies in the region, seeking to create insecurity in Iran."

Iranian President Hassan Rouhani and Foreign Minister Mohammad Javad Zarif also threw tough remarks on the United States, blaming it for provoking the attack that killed at least 25 and injured 60 others.

"When you have a security incident at home, blaming others is an enormous mistake," said Pompeo in an interview with Fox News on Sunday.

Responding to Zarif's tweet vowing to act "swiftly and decisively" "in defense of Iranian lives," Pompeo said: "I wish Zarif would focus on keeping his own people secure rather than causing insecurity all around the world."

On Saturday morning, four armed men clad in the uniform of Iranian Islamic Revolution Guard Corps (IRGC) attacked the military parade in Ahvaz, capital of Khuzestan Province, which was marking the anniversary of the Iran-Iraq war in 1980-1988.

Al-Ahvazieh, an Iranian Arab-affiliated group, has claimed responsibility for the terror attack. Shiite-dominated Iran considers the Al-Ahvazieh as a separatist and terrorist group supported by Saudi Arabia, its Sunni-majority arch rival in the Gulf.