U.S. Defense Secretary Jim Mattis has dismissed Iran's accusations that the United States was behind a deadly weekend attack on a military parade in southwestern Iran, calling the allegations "ludicrous."
Mattis pointed out to reporters at the Pentagon on September 24 that the administration of U.S. President Donald Trump condemned the attack at a military parade in the city of Ahvaz on September 22, the day it occurred. At least 25 people were killed in the incident, including a 4-year-old child.
"It's ludicrous to allege that we might have had anything to do with it," he said. "They've so far blamed at least three countries and I think one terrorist group. We'll see how long the list goes. But it'd be good if they knew what they're talking about before they started talking."
Two groups have claimed responsibility for the attack: the ethnic Arab antigovernment Ahvaz National Resistance and the extremist group Islamic State (IS).
Mattis said he wasn't concerned about Iranian vows to take revenge.
"We've been very clear that they shouldn't take us on like that, and I'm hopeful that cooler, wiser heads will prevail," he said.
U.S. Secretary of State Mike Pompeo also denied that the United States played any role in the attack.
The UN Security Council late on September 24 issued a statement condemning the incident as "heinous and cowardly."
Pompeo called the loss of lives "tragic" in an interview with Fox News and said: "When you have a security incident at home, blaming others is an enormous mistake."
Iran's supreme leader and deputy head of the Islamic Revolutionary Guards Corps earlier in the day both repeated accusations that the United States and Israel were involved in the attack and promised a "devastating" response.
"You have seen our revenge before. You will see that our response will be crushing and devastating and you will regret what you have done," Brigadier General Hossein Salami said in a speech broadcast on state television.
Supreme Leader Ayatollah Ali Khamenei alleged that the attackers were backed by the United States and paid by Saudi Arabia and the United Arab Emirates. He vowed that Iran would "severely punish" those behind the bloodshed.
Tens of thousands of people took to the streets of Ahvaz on September 24 to mourn the victims of the assault, with some chanting "Death to Israel and America."
Members of the IRGC were among those killed as gunmen fired on a viewing stand in Ahvaz where officials had gathered to watch the annual parade marking the start of Iran's 1980-88 war with Iraq.
Meanwhile, Iran's Intelligence Ministry said 22 people were arrested in connection with the attack, which it blamed on a "five-member terrorist group affiliated to jihadist separatist groups."
Weapons, explosives material, and communication equipment were also seized, a ministry statement said.
In New York, the UN Security Council issued a statement on September 24 to condemn the assault in Ahvaz, calling it a "heinous and cowardly terrorist attack."