Indonesian security forces stormed airports, glitzy hotels, passenger ships and the Jakarta Stock Exchange building Sunday in a massive anti-terrorism drill in the world's most populous Muslim nation. About 7,000 police, soldiers and emergency-response workers were taking part in the exercise held in six major cities, including the capital, Jakarta, and on the popular resort island of Bali. Indonesia has been hit by a string of deadly suicide bombings targeting Westerners in the wake of the Sept. 11, 2001, attacks on the United States. However, experts say the risk of more large-scale attacks has diminished with the arrest of hundreds of suspects. President Susilo Bambang Yudhoyono said, however, last month's terrorist rampage in the Indian city of Mumbai that left 164 dead highlighted the need to remain alert.