Protests challenging Iran's theocracy appear increasingly smothered, with authorities shutting the country off from the world and escalating a bloody crackdown. Activists say the crackdown killed at least 2,615 people. Witnesses in Tehran report no new signs of unrest, and gunfire has faded. Iranian state media announces waves of arrests, targeting those it calls “terrorists.” Meanwhile, Iran shut down its airspace for hours without explanation early Thursday. This has happened before during combat with Israel. The U.N. Security Council scheduled an emergency meeting on Iran, requested by the United States, to address the situation.