The Tehran funeral on Friday of a nuclear scientist blown up by a hitman saw the ruling clergy urge Iranians to rally behind it at a forthcoming election and face down Western threats against Iran's nuclear programme.
In a mood of high emotion in a city increasingly beset by U.S. and European sanctions and fears of war with Israel and the West, hundreds of chanting mourners carried the flag-draped coffin of Mostafa Ahmadi-Roshan, killed on Wednesday by a motorcycle assassin in rush-hour traffic.
Death to America! Death to Israel! roared the crowd streaming away from weekly prayers at Tehran University, where the dead man was hailed as a martyr in the tradition of Imam Hussein, a revered figure for Iran's Shi'ite branch of Islam.
Nuclear energy is our absolute right! young men chanted.
State radio described the 32-year-old chemical engineer, whose driver was also buried on Friday, as having worked on procurement for the uranium enrichment plant at Natanz.
That disclosure may strengthen suspicions he was targeted by Israeli and Western agencies, who say that some covert Iranian purchases confirm their scepticism of Tehran's assertion that it is not seeking to develop atom bombs.
With popular discontent growing over economic hardship and, among some, the lack of political freedoms, the clerical elite has portrayed Western hostility toward Iran's leaders and their avowedly peaceful nuclear energy programme as a spur to national unity and for suppression of dissident voices.
Ayatollah Mohammed Emami-Kashani told worshippers Ahmadi-Roshan's assassination - the latest of several attacks blamed on foreign agents - should encourage voters not to heed opposition calls to boycott a parliamentary election on March 2.
Though dissenters cannot take part, the vote will be a first test for an increasingly fractured leadership since big street protests followed the re-election of President Mahmoud Ahmadinejad in August 2009 and since popular uprisings against autocracy hit Iran's Arab neighbours, including ally Syria.
The nation should wake up, Emami-Kashani said in his sermon, repeating a warning by Supreme Leader Ayatollah Ali Khamenei that Iran's Western enemies were plotting to use the election to destabilise the 32-year-old Islamic Republic. We have the election coming up and, as the leader said, the enemy is planning for the elections. All the people should be united.
Ahmadi-Roshan, whose grieving family have been shown on national television accusing Iran's enemies of killing him, was to be interred at a shrine close to a fellow nuclear scientist assassinated in the same way two years ago, on January 12, 2010.
Ahmadinejad, away on a tour of Latin America, said: Once again the dirty hands of arrogance and the Zionist elements have deprived our scientific and academic community of the graceful presence of one of our young intellectuals and scientists.
Those criminals who think they can impede Iranian intellectuals and elites in their growth and evolution should know that such behaviour does not only not prevent the dear country from its development path but it multiplies Iranians' will and determination to pursue their national pride in the world's scientific fields, ISNA news agency quoted him saying.
Mohammad Javad Larijani, secretary-general of the Iranian High Council for Human Rights, has written to the U.N. human rights commissioner calling for a committee to be set up to investigate the killing, Fars news agency said. U.N. officials have said extrajudicial executions are illegal, but that it is up to Iran in the first instance to investigate the killing.
Israel, which has floated threats of military action to thwart any Iranian nuclear weaponry, has made no comment.
Presumed owner of the Middle East's only atomic arsenal, Israel has a history of killing enemies abroad and had warned Iran only this week to expect more unnatural mishaps if it pursued its research and development in nuclear science.
Some Iranians have called for reprisals against Israel.
The United States, sympathetic to its ally's view that an Iranian atomic bomb could threaten the Jewish state's existence, has strenuously denied killing the scientist and says it is sticking to economic sanctions to change Tehran's mind.
We have some ideas as to who might be involved, U.S. Defense Secretary Leon Panetta said on Thursday.
But we don't know exactly who was involved.
U.S. and European efforts to cripple Iran's finances by discouraging or banning countries and firms from importing its oil have been proceeding, though China, Iran's biggest customer, is reluctant to oblige and other countries too fear that to stop purchasing Iranian crude could badly hurt their own economies.
Japan's policy on Iranian oil was left in doubt on Friday after the prime minister distanced himself from his finance minister's pledge to reduce oil imports in support of the U.S. push to prevent Iran from making nuclear weapons.
The standoff over the nuclear programme, including a threat by Iran to block the Gulf oil shipping lanes and a U.S. warning of naval action to keep them open, has sent world oil prices higher and fuelled fears of a major conflict in a region already electric with tension between an array of competing interests.
However, analysts and diplomats also note that rhetoric and symbolic actions are not new, and that diplomacy has defused previous crises before an outbreak of conflict that probably would not serve the interests of any of the established powers.
One Western diplomat who follows negotiations on Iran's nuclear programme closely said: I'm completely unable to say which way the situation will develop.
If you constantly get diverging statements and decisions from various parts of the Iranian regime it is difficult to say how far it is intentional and how much it is a result of the internal competition and the fact that it is a country with multiple centres of power.
Western diplomats say that Iran will need to show genuine readiness to address mounting suspicions about its nuclear programme at rare talks with senior U.N. officials this month to convince a sceptical West that it is not just playing for time.
A high-level team from the U.N. atomic watchdog is expected to visit Tehran later this month to discuss its growing concerns, according to diplomatic sources.
Iran's envoy to the International Atomic Energy Agency (IAEA) has said the Islamic Republic is ready to answer the agency's questions in order to remove any ambiguities about its nuclear work and clear up the issue once and for all.
But Iranian officials have used such language before, without this leading to concrete progress, and diplomats say this will not be enough to satisfy the IAEA mission, including the agency's chief safeguards inspector, Herman Nackaerts.
One Western envoy said: This road is paved with danger and past experience cannot render anyone optimistic.
Nackaerts, IAEA Assistant Director General Rafael Grossi and other senior officials will probably visit around January 28.
The Iranian leadership has come under increased pressure since the IAEA reported in November that Tehran appeared to have worked on designing a nuclear weapon and that secret research to that end may be continuing. Iran says it wants only nuclear power and some other civilian types of radioactive material.
This week, its announcement that it was enriching uranium at a new and potentially bombproof underground plant, as well as the sentencing to death of an Iranian-American dual-national for spying, have added to friction with the Western powers.
However, last month Tehran also renewed an invitation for the senior IAEA team to visit Tehran. And it has signalled a readiness to resume talks with big powers that have been frozen for a year over its refusal to discuss suspending enrichment.
Western diplomats have often accused Iran of deploying stalling tactics in the nuclear standoff with the powers, including the United States, China and Russia, to buy more time while it advances its atomic activities.
Some experts reckon Iran could have enough highly enriched uranium for one bomb next year, giving it a possibility of then, at some future date, constructing a viable weapon within months.
(Additional reporting by Ramin Mostafavi, Mitra Amiri and Zahra Hosseinian in Tehran, Stanley White in Tokyo, Fredrik Dahl in Vienna; Writing by Alastair Macdonald; Editing by Mark Heinrich)