"Based on preliminary reports, many takfiri terrorists and the leaders responsible for the terrorist crime in Ahvaz have been killed or wounded in this missile attack", the Guards added.
"The headquarters of those responsible for the terrorist crime in Ahvaz was attacked a few minutes ago east of the Euphrates by several ballistic missiles fired by the aerospace branch of the Revolutionary Guards", the Guards said on their website.
The attack adds to confusion over who carried out an assault on a military parade in Ahvaz on September 22 that killed at least 24 people and wounded over 60.
The town of Albu Kamal itself is held by regime forces and allied regional militiamen who seized it from IS in 2017.
Iranian authorities have blamed Arab separatist movement the Ahwazi Democratic Popular Front (ADPF) as the main suspect but also directed accusations at the United States, Israel and Gulf Arab monarchies for the suspected financing, recruiting and training of Sunni terrorists involved. However, the city has been targeted even now by IS militants who have lost nearly all the territory they once held in both Syria and Iraq.
Iranian media said the attacks "killed and wounded" militants in a "terrorist headquarters", without elaborating.
Iran's Supreme Leader Ayatollah Ali Khamenei had said the deadly Iran attack was linked to the United States' "allies in the region".
Netanyahu spoke after Iran fired missiles featuring slogans urging "Death to Israel" and "Death to America" at Islamic State targets in Syria earlier Monday that it said were connected to the attack.
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Instead, he noted, the U.S.is continuing sanctions aimed at keeping up pressure. But denuclearization negotiations have stalled. He then added: "I didn't give up anything".
It is Iran's third time launching ballistic missiles in a show of force over the past two years.
"This is the roaring of missiles belonging to the Revolutionary Guard of the Islamic Revolution", an Iranian state TV reporter said as the missiles launched behind him.
A Syria-based official with the so-called "Axis of Resistance" led by Iran, which includes Iran, Syria, the Lebanese militant Hezbollah and other groups fighting alongside Assad's forces said the missiles hit "the last pocket held by Daesh" in Syria, using an Arabic term to refer to IS. State TV aired footage of a drone dropping what appeared to be an unguided munition.
Iran initially blamed Arab separatists for the attack in which gunmen disguised as soldiers opened fire on the crowd and officials watching the parade from a viewing platform.
Both the Islamic State group and an Arab separatist group have claimed the assault.
The missiles were fired from western Iran and traveled the length of Iraq to reach targets in the Albu Kamal region of Syria, a distance of approximately 570 kilometers (350 miles), Fars reported.
Describing the attack on defenseless people as an act of cowardice, the Leader noted, "According to [available] reports, this cowardly act has been perpetrated by the same people who are saved by Americans whenever they face a hard situation in Iraq and Syria" and whose operations are being financed by Saudi Arabia and the United Arab Emirates. Last month, Iran fired missiles at Kurdish militants based in Iraq.