Thousands of Iranians took to the streets of central Tehran for more anti-regime protests, but the overwhelming presence of vigilantes and police meant the fifth consecutive night of demonstrations was largely a muted affair. Feeling the pressure from all sides, Tehran also hit out at Washington after the White House said it was "alarmed" by the crackdown. The foreign ministry said such comments constituted a "flagrant example of interference in Iran's internal affairs". Overnight Saturday, only limited and sporadic clashes were reported around Tehran university's campus, the focal point of vitriolic student-led protests that have targeted the very top of Iran government. Large numbers of cars were seen driving in areas around the campus in the early hours of Sunday, but the would-be demonstrators were matched in numbers by police and bussed-in members of the Basij militia -- among the toughest defenders of the nearly 25-year-old Shiite clerical regime. Club and chain-wielding members of the Ansar Hezbollah group were also on patrol. Such was the overpowering presence of security forces and militiamen that few drivers dared even to honk their horns in support of the student-led protest movement. On previous nights, a number of drivers adding to the cacophony of defiance had had their windscreens smashed in or had been dragged from their vehicles and beaten up. But overnight Saturday, no slogans were heard being shouted either, and the demonstration -- more of a frustrating traffic jam -- was largely calm, in contrast to previous nights which saw spiraling tensions, fierce clashes and slogans directed at Iran's supreme leader Ayatollah Ali Khamenei. However, there were reports of renewed clashes in the southern city of Shiraz, with the student news agency ISNA saying demonstrators there again shouted virulent slogans that resulted in a number of them being arrested. There were conflicting reports that a protestor had been killed there during Friday night's clashes. Demonstrations have also been reported in the southeastern city of Ahvaz and historic Isfahan in the centre. Over the past five nights in Tehran, scores of people have been injured or arrested, while bank windows, cars and motorcycles have also been smashed up. Khamenei has accused arch-enemy the United States of orchestrating the unrest. Many protestors seeking to join the fray were answering calls from US-based Iranian opposition-run Persian language satellite television channels -- notably the Los Angeles-based pro-monarchist NITV. State television and radio also accused foreign media of distorting their coverage of unrest in line with an "imperialist and Zionist" plot against the Islamic republic. Foreign media in Tehran have received a written recommendation from the authorities to keep away from the scene of the protests. The crackdown has also included the arrests of leading members of Iran's liberal opposition, critical of certain facets of the Islamic regime. Some vigilantes were also reportedly detained in the security sweep, in which authorities have been keen to keep student protestors and the Shiite militias apart. During the protests, the first to rock Iran for six months and the most violent since July 1999 when at least one student died, virulent slogans have been shouted against Iran's leaders, including Khamenei, calling for them to step down. Criticising the supreme leader is a serious offence in Iran. Many protestors also called for the resignation of embattled President Mohammad Khatami, who was elected with landslide majorities in 1997 and again in 2001. **PHOTO CAPTION*** Broken doors of the student's room are seen at the Hemmat dormitory of the Allameh Tabatabai University in Tehran, Iran, Saturday, June 14, 2003. (AP Photo/ILNA)