Iran's Revolutionary Guards ratcheted up the tensions with Saudi Arabia as it accused its regional rival of involvement in Wednesday's double terrorist attack in Tehran, which left at least 12 people dead and wounded more than 40.
Five suspects have been detained following the attacks, the city’s police chief said on Wednesday evening.
General Hossein Sajedinia told the semi-official ISNA news agency on Wednesday night that police are interrogating the suspects.
He did not elaborate, but said Tehran is safe and police and other security forces are deployed and closely monitoring the Iranian capital.
The deputy head of the National Security Council said in an interview on state television that the assailants were from Iran.
"About the identity of the attackers I should say they were from parts of Iran, and had joined Daesh [Islamic State]," Reza Seifollhai said.
Gunmen and suicide bombers launched simultaneous attacks on the parliament building in Tehran and the nearby shrine of Ayatollah Ruhollah Khomeini, the Islamic Republic’s founder.
First significant strike
The attacks were claimed by Islamic State, also known as Isis, in what would be the jihadi group's first significant strike in the Islamic Republic. However a statement from the Revolutionary Guards linked the "brutal attack" to Donald Trump's visit last month to Riyadh, where the US president singled out Iran for fuelling "the fires of sectarian conflict and terror".
“This terrorist act took place a week after a joint meeting between the US president and head of a reactionary regional country [Saudi Arabia] which has been a constant supporter of terrorism,” the statement said. “The fact Isis claimed responsibility proves that they [Saudi Arabia] were involved in the brutal attack.”
Hassan Rouhani, Iran's president, condemned the attacks, without laying the blame at the feet of Saudi Arabia. However, the accusation from the powerful Revolutionary Guards will stoke the increasingly bitter enmity between Tehran and Riyadh, which are involved in proxy wars from Syria to Yemen.
It also comes at a sensitive moment in the Gulf, where a new rift opened this week pitting Qatar, with which Tehran has ties, against Saudi Arabia, the United Arab Emirates, Egypt and Bahrain. The quartet on Monday severed diplomatic ties with Qatar and accused Doha of supporting terrorism.
‘Supporting terrorism’
Hamid-Reza Taraghi, a senior politician close to Tehran’s hardliners, blamed a combination of Saudi Arabia, the US, Islamic State and the exiled opposition group MEK for Wednesday’s attacks. “Saudi Arabia is definitely playing the leading role in these incidents, considering that its foreign ministry threatened Iran two to three days ago,” he said, referring to a call by Riyadh for Iran to be punished for supporting terrorism. He provided no evidence to support his claims.
His view was echoed by others, though they did not provide evidence either. "The fact that these two attacks took place ... after that [Riyadh] meeting means that both the US and the Saudi regime have ordered their proxies to embark on that act," Brig Gen Hossein Nejat of the Revolutionary Guards told a local news agency.
Mohsen Rezaei, a former Revolutionary Guards commander, warned terrorists to expect a "tough and unforgettable" response from Iran.
Mr Trump’s administration is viewed as much more hawkish on Iran that the previous government of Barack Obama. Tehran has long accused Saudi Arabia of supporting Islamic State.
The assault began at 10.30am local time when four gunmen in women’s clothing walked into the building and began shooting. One detonated an explosives vest. All the attackers were killed after a stand-off lasting several hours, Iran’s interior ministry said.
Two further gunmen also opened fire at the Ayatollah Khomeini shrine in the Iranian capital. One was reported to have killed himself by detonating an explosive vest. Another was shot dead. Based on a video released by Islamic State, the attackers spoke Arabic. Brig-Gen Nejat said their nationality was not yet clear.
At least 12 people were killed in the two attacks, Pir-Hossein Kolivand, head of Iran’s emergency department, was quoted as saying by Tasnim news agency.
Islamic State on Wednesday threatened further attacks on Iran, saying “Persia should know that the state of the caliphate will not miss an opportunity for an onslaught against them.”
Islamic State presence
Terrorist attacks are rare in Iran, which keeps a tight grip on domestic security. The country has largely been spared from militant attacks, despite its heavy support of Shia militias in Syria and Iraq, which has increased sympathies among some of those countries' Sunni populations for radical groups such as Islamic State.
If Iran steps up its fight against Islamic State in the wake of Wednesday's attack, the situation in the region could become even more volatile, analysts say. Charlie Winter, senior research fellow at the International Centre for the Study of Radicalisation at King's College London, said the attack could boost Islamic State's flagging morale and intensify pressure on Tehran to step up its involvement in Syria against the jihadis. "If this happens, a more intense 'Sunni war against Shia Islam' will pour petrol on Isis's ideological fire," he said.
Security analysts outside of Iran have long argued that it has not been attacked because it tolerated the presence of al-Qaeda and the movement of communications and finances through the country. But for Islamic State, which is not reliant on foreign financing, Iran has long been a target.
While it is difficult to gauge the extent of an Islamic State presence in Iran, the group has long sought to attract people from Iran’s Sunni minority. Last March, it released a 36-minute video in Persian, vowing to conquer Iran. In the video, militants used photographs of Iranian leaders for target practice, including Qassem Soleimani, commander of the Revolutionary Guards’ elite Quds force.
Copyright The Financial Times Limited 2017
Additional reporting: Wire agencies