UN Secretary-General Antonio Guterres on Tuesday expressed his regret at the rising death toll in anti-government protests in Iran, and called on the Islamic Republic to respect the rights of peaceful protesters.<br/><br/>Tehran said, 21 people had died in clashes across the country as thousands of people took to the streets. Police have arrested hundreds of demonstrators.<br/><br/>Iran's Supreme leader Ayatollah Ali Khamenei had blamed the country's enemies earlier today for almost six days of deadly unrest that have shaken the conservative country.