Enlarge By Strdel, AFP/Getty Images Indian security officials inspect the site of a blast at a 'ghat' (bathing point) in Varanasi on Tuesday. LUCKNOW, India (AP)  A bomb hidden in a metal canister exploded during a Hindu ceremony Tuesday evening, wounding 20 people, including four foreigners, in India's holy city of Varanasi. Police said the blast appeared to be a terrorist attack but would not say who they suspected. The bomb was stashed in a milk container on the Sheetla Ghat, one of many stone staircases leading to the Ganges river, the site of daily spiritual rituals, according to police official Brij Lal. The force of the explosion ripped away a metal railing and damaged stones up to 200 feet (60 meters) away, said a witness, Ramatama Srivastava. Three victims, including one of the foreigners, were hospitalized in serious condition. It was not immediately clear where the foreigners were from. Srivastava — who spoke by telephone from Varanasi, which is about 180 miles (300 kilometers) southeast of the Uttar Pradesh state capital of Lucknow — said he noticed the foreigners were watching the Hindu prayer ceremony and taking photographs. Every day, priests and others light oil lamps, ring bells and chant prayers to worship the Ganges in Varanasi, the holiest city in the Hindu religion. In March 2006, twin bombings blamed on a Pakistan-based Islamic militant group tore through a train station and a temple in Varanasi, killing 20 people. Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more