Iranian protesters ransacked and set fire to part of the Saudi Embassy in Tehran on Saturday after Saudi Arabia executed an outspoken Shiite cleric who had criticized the kingdom's treatment of its Shiite minority.
Protesters broke furniture and smashed windows in an annex to the embassy, said a witness who was reached by telephone from Tehran. The protesters also set fire to the room, said the witness, who would provide only his first name, Abolfazl, because he had been involved in the protest.
The police arrived and cleared the embassy grounds of protesters and extinguished the fire, he said.
The protest against the execution of the cleric, Sheikh Nimr al-Nimr, turned violent after participants began throwing Molotov cocktails at the embassy and then broke into the compound.
Al-Nimr was executed in Saudi Arabia along with 47 men on terrorism-related charges, drawing condemnation from Iran and its allies in the region as well as protests around Iran and in other countries.
Saudi officials said the mass execution, one of the largest in the kingdom in decades, was aimed at deterring violence against the state. But analysts said that the grouping of the cleric, Sheikh Nimr al-Nimr, with hardened jihadis was a warning to domestic dissidents that could exacerbate sectarian tensions across the Middle East.
The executions were the first of 2016 and followed a year in which at least 157 people were put to death, the Muslim kingdom's highest yearly total in two decades.
They coincided with increased attacks in Saudi Arabia by the jihadis of the Islamic State and an escalating rivalry between the Sunni monarchy and Shiite Iran that has fueled conflicts in Syria, Yemen and elsewhere.
Many in the region see the execution of al-Nimr as part of that rivalry, and Shiite leaders in different countries condemned the move. Al-Nimr was an outspoken critic of the Saudi monarchy and was adopted as a symbolic leader by Shiite protesters in several Persian Gulf countries during the Arab Spring uprisings.
"It is clear that this barren and irresponsible policy will have consequences for those endorsing it, and the Saudi government will have to pay for pursuing this policy," said Hossein Jaberi-Ansari, a spokesman for Iran's Foreign Ministry.
Criticism also came from Shiite politicians and clerics in Iraq, the Houthi rebel movement in Yemen and the Lebanon-based militant group Hezbollah. In Iraq, Prime Minister Haider al-Abadi wrote on Twitter that he was "shocked" and "saddened" at al-Nimr's execution. "Peaceful opposition is a fundamental right," he wrote.
"Repression does not last."
Hundreds of Shiites took to the streets to protest in eastern Saudi Arabia and in Bahrain, witnesses said.
In Iran, protesters tore down a flag from the Saudi Consulate in the city of Mashhad, and demonstrations were planned for Sunday in Tehran.
Saudi officials denied that sectarianism had played any role in the executions.
"This means that Saudi Arabia will not hesitate to punish all terrorists," said Anwar Eshki, a retired major general in the Saudi army who is the chairman of a research center in Jiddah.
When asked about al-Nimr, Eshki replied, "In Saudi Arabia, there is no difference between the criminals."
Saudi allies like Bahrain and the United Arab Emirates defended the kingdom.
In executing al-Nimr, Saudi Arabia had sent a "message of determination" to Iran, an Emirati political scientist, Abdulkhaliq Abdulla, wrote on Twitter, adding that the kingdom was better prepared to confront Iran "than at any other time."
Most of those executed on Saturday had been convicted in connection with deadly attacks by al-Qaida in the kingdom about a decade ago. Four, including al-Nimr, were Shiites accused of violence against the police during protests.
In recent weeks, the Saudi government appeared to be preparing the public for the executions. Reports that they were imminent had appeared on Saudi news websites, and Al-Arabiya, a Saudi-owned satellite channel, recently aired a multipart documentary that dramatized the kingdom's fight against al-Qaida.
On Saturday, some Saudis, including journalists at a government news conference, thanked officials for carrying out the death sentences. The top cleric, Grand Mufti Sheikh Abdulaziz Al Sheikh, called them a "mercy to the prisoners" because the executions would save them from committing more evil acts.
But some Western analysts said that executing al-Nimr along with Qaida militants conflated his outspoken activism with a grave national threat.
"This is indicative of the hard-line tilt the regime has taken," said Frederic Wehrey, an analyst at the Carnegie Endowment for International Peace who has traveled in Shiite parts of Saudi Arabia.
Al-Nimr, said to be in his mid-50s, was from Awamiyah, a poor town surrounded by palm groves in eastern Saudi Arabia that is known for opposition to the monarchy.
He studied in Iran and Syria, but rose to prominence for fiery sermons after his return that criticized the ruling family and called for Shiite empowerment, even suggesting that Shiites could secede from the kingdom.
This gained him a following mostly among young Shiites who felt discriminated against by Persian Gulf governments. When these young people joined Arab Spring protests in Bahrain and eastern Saudi Arabia in 2011, al-Nimr became a leading figure.
During a sermon in 2012, al-Nimr mocked Prince Nayef bin Abdulaziz, who had been the Saudi interior minister and had recently died.
"He will be eaten by worms and suffer the torments of hell in the grave," al-Nimr said. "The man who made us live in fear and terror; shouldn't we rejoice at his death?"
Nayef's son, Mohammed bin Nayef, is now the crown prince and runs the Interior Ministry, which carries out death sentences.
The Saudi authorities arrested al-Nimr in July 2012, while the kingdom was leading a regional push to end the pro-democratic activism of the Arab Spring. This included sending tanks to prop up the Sunni monarchy in Bahrain, which faced protests led by the country's Shiite majority.
Shiites also protested in Saudi Arabia's oil-rich Eastern province, where many Shiites live and complain of discrimination.
Hundreds of people demonstrated in the province after video footage emerged of al-Nimr's arrest that showed him bleeding while in custody. The government said he had been wounded in a shootout. Al-Nimr faced charges including sedition and was sentenced to death in October 2014.
Despite al-Nimr's fiery tone, his supporters and others who followed his career said he had not called for violence. "To lump this guy with terrorists is a stretch," Wehrey said. "To my knowledge, he never called for armed insurrection."
The executions came as Saudi Arabia sought to battle comparisons between its application of Shariah law and that of the Islamic State, the Sunni extremist group. Most of the executions Saturday were by beheading; they were not public, unlike most Saudi executions. On Saturday, an image was posted on the website of the supreme leader in Iran, Ayatollah Ali Khamenei, depicting what appeared to be an Islamic State fighter about to kill a hostage and a Saudi executioner with a sword, with the question "Any differences?"
Saudi officials say their government puts to death only people who have been convicted of grave crimes, unlike the Islamic State, which kills hostages and releases grisly videos.
But human rights groups have criticized the Saudi justice system for not following due process by denying the accused access to legal counsel during interrogation and indicting suspects on vague charges like adopting extremist ideology or undermining the stability of the state.
The last mass execution of similar scale in Saudi Arabia was in 1980, when 63 jihadis were put to death after they seized the Grand Mosque in Mecca.
The executions of at least 157 people in 2015, a year that began with the inauguration of a new monarch, King Salman, were a sharp increase from the 90 people put to death in 2014. Saudi officials have argued that the increase reflects not a change in policy but a backlog of death sentences that had built up in the final years of the previous monarch, King Abdullah.