TEHRAN: Demonstrators chanted “Down with America” outside the former US Embassy and pelted the British diplomatic compound with eggs and tomatoes Thursday in separate rallies held under tight security but without challenges from opposition groups. The protests outside the former American Embassy were well-scripted events to mark the anniversary of the 1979 storming of the site - which began a 444-day hostage crisis and severed Washington's ties with Iran. Despite the familiar chants against the US protesters did not appear to burn US flags in what could be a rare nod of approval to Washington for adding an Iranian group to it's terrorist list. The anti-British demonstration, however, included the Union Jack going up in flames. The protest appeared to be reaction to Iran's announcement that it arrested four suspected members of a Kurdish rebel group with a top official allegedly living in Britain. Last year, the annual pro-government event outside the brick walls of the former US Embassy brought clashes and chaos to central Tehran after protesters held counter-marches over their claims of massive vote rigging in the presidential election. But it was among the last major displays of opposition anger on the streets. Embattled authorities began stepping up their crackdowns and threats to quell the most serious domestic unrest since the 1979 Revolution. This year, security forces were on high alert for any hint of dissent. The opposition Jaras website posted a statement applauding the “brave” takeover of the US Embassy to protest American support for the pro-Western shah, who had been toppled by the Revolution months earlier.