A crackdown on nationwide protests in Iran has killed at least 544 people and even more are feared dead, activists have said, while Tehran warned that the US military and Israel would be legitimate targets if America uses force to protect demonstrators. Another over 10,600 people have been detained over the two weeks of protests, said the US-based Human Rights Activists News Agency on Sunday, which has been accurate in previous unrest in recent years. It relies on supporters in Iran crosschecking information. It said 496 of the dead were protesters and 48 were with security forces. With the internet down in Iran and phone lines cut off, gauging the demonstrations from abroad has grown more difficult. The Associated Press has been unable to independently assess the toll. Iran's government has not offered overall casualty figures. Those abroad fear the information blackout is emboldening hard-liners within Iran's security services to launch a bloody crackdown. Protesters flooded the