Thousands mourn Tehran victims as officials lambast US, Saudi

Tens of thousands of mourners gathered in Tehran on Friday for the funerals of victims in deadly twin attacks on the city last week, with Iranian officials turning their wrath against the United States and Saudi Arabia.

Crowds who gathered behind a lorry carrying the coffins of 15 of the 17 victims shouted "Death to America", "Death to the Saud" ruling family, and "We are not afraid", after attacks on Wednesday shook the capital.

Burials were held in the provinces for the two others killed when suicide bombers and gunmen stormed Tehran's parliament and the shrine of revolutionary leader Ayatollah Ruhollah Khomeini.

Supreme leader Ayatollah Ali Khamenei castigated the US and Saudi Arabia in a message of condolence to the families of the dead, having previously played down the attacks.

"Such acts will have no other result than to reinforce hatred for the US government and its agents in the region, like the Saudi (government)," he wrote.

Iran's parliament speaker Ali Larijani also attacked the United States and Saudi Arabia, which he called "a tribal state very far from anything like a democracy".

The US "knows that the Revolutionary Guard and its Qods Force are the most important regional forces fighting terrorists", he said during a speech at the ceremony in which he also denounced US sanctions over its ballistic missile programme.

The imposition of such sanctions "demonstrates their alignment with terrorists in the region", said the speaker.

After prayers at Tehran University a long procession left the centre of the capital for the Behesht-e-Zahra cemetery near the Khomeini mausoleum, 20 kilometres away.

The attacks in Tehran were carried out by five men and claimed by the Islamic State, the first time the group had targeted the country.

The attackers are all Iranian and are thought to have travelled to Iraq and Syria after joining the group. Nine people with links to IS were detained on Friday, Iran's judiciary said.

Since Trump took office in January, relations between Washington and Tehran have soured, and while on a recent trip to Saudi Arabia Trump lambasted Iran for its alleged support of terrorist groups.

Iran's Revolutionary Guards has accused regional rival Saudi Arabia of involvement in Wednesday's attacks.

But Intelligence Minister Mahmoud Alavi said on Thursday that "we still cannot judge that Saudi Arabia has had a role in this terrorist incident".