A suicide bomber killed 27 members of the Islamic Revolutionary Guards Corps and wounded 13 on a bus in a restive region of southeast Iran on Wednesday, Iranian media reported. It was among the deadliest attacks in Iran in years.

The Revolutionary Guards quickly blamed the United States for the assault, which came during the week that Iran’s leaders have been celebrating the 40th anniversary of the Islamic Revolution that overthrew the US-backed shah in 1979.

The Revolutionary Guards did not explain precisely how the United States could have been involved in the attack.

Dispatches by the official Islamic Republic News Agency and the Fars News Agency said the victims had been travelling between the cities of Zahedan and Khash near the Pakistan border, a haven for militant separatist groups and drug smugglers.

There were conflicting accounts of the casualties, which often happens in Iran immediately after calamities. Fars initially reported that at least 20 people had died, then updated the death toll to at least 41 – suggesting that everyone on the bus had been killed. Without explanation, Fars later adjusted the toll to 27 dead and 13 wounded, consistent with what the Revolutionary Guards and other news services were saying.

Responsibility

Fars said a bomber driving a car full of explosives on a highway had detonated it near the bus, and a video posted on the agency’s website showed what it said were the charred remains of the bus.

On the social messaging app Telegram, a militant group called Jaish al-Adl claimed responsibility for the attack, but officials did not confirm that the group was involved.

A statement issued by the Revolutionary Guards said the bus had been “carrying the warriors of Islam soldiers who were returning from the region to their cities after completing their border mission”.

While the US and Israel have accused Iran of fomenting terrorism in the Middle East, Iran itself has also been the target of terrorist attacks in the 40 years since the Islamic Revolution.

Previous attacks

In September, gunmen killed at least 25 people and wounded 60 in an assault on a military parade in Ahvaz, in southwestern Iran, where Arab separatists are active. The victims were a mix of Revolutionary Guards members and civilian onlookers.

Less than two years ago, armed assailants, some disguised as women, stormed the parliament building and the tomb of Iran’s revolutionary founder in co-ordinated assaults that left at least 12 people dead.

The Islamic State group claimed responsibility, boasting that the attacks were its first against Iran, where the Shia Muslim majority is loathed by Islamic State’s Sunni extremist ideologues.

A southeastern Iranian province, Sistan and Baluchistan, is home to several extremist Sunni groups that have committed sporadic bombings, assassinations and other attacks on Iranian security forces and officials.

The latest attack came against the backdrop of a two-day diplomatic meeting in Warsaw, Poland, organised by the United States and aimed partly at pressuring and isolating Iran.

Iranian leaders have often accused the United States and its key Middle East allies, Saudi Arabia and Israel, of supporting armed opposition groups inside Iran with money, intelligence and weapons.

Representatives of at least one Iranian opposition group, the Mujahedeen-e-Khalq, or MEK, were present at the Warsaw meeting. – New York Times