TEHRAN, Iran—The months-long confrontation between Iran's budding opposition movement and a hard-line government determined to stamp it out escalated sharply over the weekend, as parts of the capital became engulfed in fiery political protest and demonstrations broke out across the country on the occasion of an important Shiite religious holiday.
Opposition websites reported as many as nine people killed in Tehran and the western city of Tabriz on Sunday during Ashura, a commemoration of the 7th century martyrdom of Imam Hussein, a grandson of the prophet Muhammad. Officials put the death toll at five.
Among those allegedly shot dead by government security forces or allied militias was Ali Habibi-Mousavi, described by websites as the nephew of opposition leader Mir-Hossein Mousavi.
Despite a heavy crackdown, the protest movement that emerged from Iran's disputed June 12 presidential election has grown increasingly daring, with members who seek an abolition of Iran's theocratic system becoming more vocal as more religious and traditional social groups identify with the opposition.
More demonstrations are expected with burial of Habibi-Mousavi, 38, today and on the religiously significant third, seventh and 40th-day grieving ceremonies for him. Such cycles of protests linked to mourning ceremonies for slain protesters helped dislodge Mohammed Reza Shah Pahlavi three decades ago.
Police denied opening fire on demonstrators, blaming the violence on "mysterious" forces. Iranian officials confirmed 300 arrests and five deaths in the clashes, but several appeared to have died in accidents.
"According to reports, one person was killed with a bullet," said Brig. Gen. Ahmad-Reza Radan, deputy commander of the police force, according to state media. "In light of the fact that the police did not use guns, this incident is very suspicious and is being investigated."
He said "tens" of police officers were wounded in the unrest.
On state television, a news announcer condemned the "riot staged by counterrevolutionary groups" and reported that the protests were "suppressed thanks to the presence of the public." The report maintained the official line that the ongoing wave of anti-government protests is a conspiracy hatched by Iranian exiles and foreign governments.
Reformist websites and witnesses also reported clashes and protests in the holy city of Qom, in the central cities of Esfahan, Shiraz, Arak, Najafabad and Kashan, in Babol in the north and in Mashhad in the east.
In Washington, the White House "strongly condemned" what it described as an official attempt to suppress the rights of Iranian civilians.
"Hope and history are on the side of those who peacefully seek their universal rights, and so is the United States," White House National Security Council spokesman Mike Hammer said in a statement.
The harrowing weekend of rolling clashes between police and protesters coincided with both Ashura and the seventh day of mourning after the Dec. 19 death of a leading dissident cleric, Ayatollah Hossein Ali Montazeri.
The weekend's slogans were more radical, with protesters not only questioning the disputed June 12 reelection of President Mahmoud Ahmadinejad, who faced the senior Mousavi and other challengers, but also shouting slogans against Iran's supreme leader, Ayatollah Ali Khamenei.
And tactics became bolder, with demonstrators targeting police vehicles, setting vans and motorcycles on fire, and burning down an office of the pro-government Basiji militia.
One video shows protesters pulling a policeman out of a van in an apparent attempt to free demonstrators locked inside. Another taken from the back seat of a car shows a swarm of demonstrators confronting armed police, overpowering and pushing the officers aside.
"Young boys, even younger than me, braved all the tear gas, and motorcycles of the anti-riot police storming them," said Ehsan, a 22-year-old student at Tehran's Science and Technology University who has attended all the protests. He asked that his full name not be used.
"Some of the young people, only holding sticks . . . counterattacked the anti-riot police and Basijis," he said. "As soon as they were beaten up or dispersed by tear gas they appeared on some other corners. I have never remembered such a day with so many brave people."
Across the capital, witnesses described scenes of pandemonium, which were confirmed by video posted online. They were the most violent protests since June 20 clashes after the election.