In a gesture of support with the Palestinians in Gaza, Iran's top leader Ayatollah Ali Khamenei, issued a religious opinion, or fatwa, declaring the purchase of any Israeli goods or trade with Israeli companies to be forbidden. Iranian authorities issued an order last week banning international companies from working in Iran if they are found to have any shares owned by Israelis. And on Sunday, the Iranian government said it plans to impose sanctions on foreign companies in Iran who also deal with Israel. It is not clear how or when the ban might be carried out, and no details were given regarding the sanctions. In the fatwa posted on his Web site, Khamenei said Muslims throughout the world must avoid the purchase, import, and promotion of any products Israelis may profit from. "All Muslims are required to avoid purchase and use of goods that bring profit to Zionists who are at war with Islam and Muslims," Khamenei said. A fatwa is a religious opinion that Muslims obey if they revere the person issuing it, which in the case of Khamenei would be restricted largely to Shiites in Iran and other parts of the world.