Iran's Khamenei vows revenge over Nasrallah's killing

Ayatollah Ali Khamenei, Iran's Supreme Leader, promised retaliation for Hezbollah leader Hassan Nasrallah's killing and declared five days of mourning. He affirmed that Nasrallah's fight against Israel would continue. Iranian officials accused the U.S. of complicity due to its support for Israel, while security in Iran has been tightened.