TEHERAN (AFP) - A suicide car bombing on a Revolutionary Guards bus in southeastern Iran killed 27 troops on Wednesday (Feb 13), in one of the deadliest attacks on the elite forces in years.
The assault came as the troops were returning from a border patrol mission, the Guards said in a statement.
"In this terrorist attack 27 of Islam's brave warriors were killed and 13 were wounded," the statement read, accusing "world domination and Zionist intelligence agencies" of supporting the attackers.
Earlier the official IRNA news agency said, "the suicide attack on an Islamic Revolutionary Guards Corps personnel bus happened on the Khash-Zahedan road."
A picture released by the semi-official Fars news agency showed a hulk of twisted metal lying by the side of a road, unrecognisable as a bus.
The attack happened when "a car filled with explosives blew up besides a bus," the Guards said.
"Mercenaries of intelligence agencies of world arrogance and domination," carried out the attack to counteract "the victory of the 40th anniversary of the Islamic revolution," they added.
Iran has been celebrating the 40th anniversary of the return to Teheran of Ayatollah Ruhollah Khomeini in 1979 after more than 14 years in exile and the overthrow of the pro-Western shah. His arrival triggered the start of the Islamic Revolution and led to the creation of the Islamic Republic.
Wednesday's attack took place in the volatile southeastern province of Sistan-Baluchistan which has a large, mainly Sunni Muslim ethnic Baluchi community straddling the border with Pakistan.
The SITE Intelligence Group reported that the attack was claimed by Jaish al-Adl, a militant group formed in 2012 as a successor to the Sunni extremist group Jundallah (Soldiers of God), which waged a deadly insurgency against Iranian targets over the past decade.
The Jaish al-Adl - blacklisted as a "terrorist group" in Iran - "announced its responsibility in a brief Persian message on Feb 13, 2019," SITE reported.
The attack came on the same day as the United States gathered some 60 countries in Poland for a conference on the Middle East and Iran which they hoped would increase pressure on Teheran.
Dubbing the meeting in Poland the "WarsawCircus", Iranian Foreign Minister Mohammad Javad Zarif said it was "no coincidence that Iran is hit by terror on the very day" that the talks began in the Polish capital.
"Especially when cohorts of same terrorists cheer it from Warsaw streets & support it with twitter bots? US seems to always make the same wrong choices, but expect different results," Zarif wrote on Twitter.
He earlier blasted the two-day conference as "dead on arrival".
"It is another attempt by the United States to pursue an obsession with Iran that is not well-founded," Zarif told a Teheran news conference.
Sistan-Baluchistan has been the scene of other attacks.
On Jan 29, three members of an Iranian bomb squad sent to the scene of an explosion in its capital Zahedan were wounded when a second device blew up as they were trying to defuse it, police said at the time.
And in early December last year two people were killed and around 40 others wounded in the port city of Chabahar, also in Sistan-Baluchistan, in an attack which Zarif at the time blamed on "foreign-backed terrorists" - a reference to Sunni Muslim extremists.
Another of the bloodiest attacks in recent times to have hit Iran happened in September when assailants killed 24 people at a military parade in the southwestern city of Ahvaz.
In October, Jaish al-Adl claimed responsibility for abducting 12 Iranian security personnel near the border with Pakistan.
And in July at least 10 members of the Revolutionary Guards were killed when insurgents attacked one of their bases along the border with Iraq.