Iranian riot police clashed on Wednesday with demonstrators and foreign exchange dealers in the capital Tehran over the collapse of the country's currency, which has lost a third of its value against the dollar in a week, witnesses said. Police fired tear gas to disperse the demonstrators, angered by the plunge in the value of the Iranian rial. Protesters shouted slogans against President Mahmoud Ahmadinejad, saying his economic policies had fuelled the economic crisis. Relates stories: Germany probing illegal exports to Iran Ahmadinejad: West waging financial war on Iran US: Iran currency plunge sign sanctions are biting Protesters further criticized the Iranian government for aiding the Syrian regime at the expense of dealing with the economic situation in Iran. The rial has been plunging to record lows against the US dollar almost daily as Western economic sanctions imposed over Iran's disputed nuclear program have slashed Iran's export earnings from oil, undermining the central bank's ability to support the currency. Panicking Iranians have scrambled to buy hard currencies, pushing down the rial. With Iran's official inflation rate running at around 25 percent, the currency's weakness is hurting living standards and threatens to worsen a recent spate of job losses in Iran's industrial sector. Tehran's main bazaar, one of the city's major shopping areas, was closed on Wednesday, witnesses said. A shopkeeper who sells household goods there said that the instability of the rial was preventing merchants from quoting accurate prices. The semiofficial Mehr news agency said the bazaar was closed for security reasons. The Mehr report quoted Ahmad Karimi Isfahani, a bazaar official, as denying reports that merchants staged a protest. Police are patrolling streets where freelance money dealers work. Exchange shops are closed. The rial hit 34,500 against the US dollar Tuesday on the unofficial street trading rate. Two years ago, it was close to 10,000 rials for the dollar. Meanwhile, on Tuesday, Ahmadinejad spoke at a press conference in Tehran, saying Iran will not back down on its nuclear program despite economic pressures and Western sanctions. Speaking of the effects of the international sanctions, he said that "The enemy believes it can break the resistance of the Iranian people, but it is mistaken." AP, Reuters contributed to this report Follow Ynetnews on Facebook and Twitter Receive Ynetnews updates directly to your desktop