Al Qaeda chief Ayman al-Zawahiri has called on Muslims to kidnap Westerners, particularly Americans, who could then be exchanged for jailed jihadists including a blind Egyptian cleric convicted in 1995 of conspiring to attack the United Nations and other New York landmarks. In a wide ranging audio interview, the al Qaeda leader expressed solidarity with the Muslim Brotherhood which is facing a violent crackdown by the army-backed government in Egypt and urged unity among rebels in their fight against Syrian President Bashar al-Assad.