Iran's supreme leader said Wednesday that the government would not give in to pressure over the disputed presidential election, effectively closing the door to compromise with the opposition.
"Neither the system nor the people will give in to pressures at any price," Ayatollah Ali Khamenei said in a meeting with lawmakers Wednesday.
But the wife of opposition leader Mir Hossein Mousavi was defiant, saying protesters refused to buckle under a situation she compared to martial law.
Witnesses said protesters and riot police clashed in the streets around Iran's parliament Wednesday afternoon.
Three witnesses said hundreds of protesters gathered in a square next to the parliament building in defiance of government orders to halt demonstrations demanding a new presidential election. They said police beat the protesters with batons, fired tear gas and shot in the air. Some demonstrators fought back while others fled to another Tehran square about a mile to the north.
Amateur video showed young men and women throwing rocks and pushing barricades, one blazing, in the street. Others shouted, "Death to the dictator!"
Severe restrictions on reporters made it almost impossible to independently verify the video, as well as other reports on demonstrations, clashes and casualties. Iran has ordered journalists for international news agencies to stay in their offices, barring them from reporting on the streets.
Mousavi's Web site called the protest independent and stated that it had not been organized by the reformist candidate.
Mousavi's wife, Zahra Rahnavard, a former university dean who campaigned beside him, said on another of his Web sites that his followers had the constitutional right to protest, and that the government should not deal with them "as if martial law has been imposed in the streets."
She called for the release of all activists and others arrested at protests.
In his remarks on state television, Khamenei was adamant. "On the current situation, I was insisting and will insist on implementation of the law. That means we will not go one step beyond the law," he said.
Also Wednesday, Iran said it was considering downgrading ties with Britain, which it has accused of spying and fomenting days of unprecedented street protests over the vote. Iran expelled two British diplomats Tuesday. British Prime Minister Gordon Brown announced that two Iranian diplomats were being sent home in retaliation.
Mousavi claims that hard-line President Mahmoud Ahmadinejad stole the June 12 election through massive fraud. He has called for annulling the results and holding a new vote.
Mousavi supporters have flooded the streets of Tehran and other cities on a near-daily basis since the election, massing by the hundreds of thousands in protests larger than any since Iran's 1979 Islamic Revolution. Security forces initially stood by and permitted the demonstrations.
Khamenei said in a stern sermon broadcast to the nation Friday that Ahmadinejad was the legitimate winner. He told opposition supporters to halt their protests and blamed the U.S., Britain and other foreign powers for instigating unrest.
The government then ramped up both the use of force and its rhetoric, beating protesters, firing tear gas and water cannons at them. State media say at least 17 people have been killed in the postelection unrest. Amateur footage of a woman bleeding to death from a gunshot on a Tehran street unleashed outrage at home and abroad.
President Obama on Tuesday used his strongest language to date to denounce the violence against election protesters, expressing outrage at "threats, beatings and imprisonments." But he stopped short of suggesting any formal action against the country.
He defended what he called the consistency of his response and attempted to explain the fine line the administration has been walking since election protests erupted: responding to the violence, but maintaining a "path" for Iran's engagement in the larger international community.
"But we also must bear witness to the courage and dignity of the Iranian people, and to a remarkable opening within Iranian society," he said. "We deplore the violence against innocent civilians anywhere that it takes place."