DHAKA, Bangladesh — Three bombs exploded early Saturday morning during a giant procession here commemorating the Shiite Muslim holiday of Ashura, killing one person, wounding dozens more and unsettling a country that has little history of sectarian tension.

For weeks, Dhaka, the Bangladeshi capital, has been on edge over reports of unusual terrorist threats. After two foreigners were shot several weeks ago, some embassies warned their citizens against walking outside or attending large gatherings.

Saturday’s bombings were the first time Shiite Muslims had been targeted in Bangladesh, officials said. Before resuming the procession hours after the blasts, marchers stood mutely over flyspecked smears of blood where a boy had been fatally wounded.

The boy was identified as Sajjad Hossain Sanju, 16, said an officer at the Chawkbazar Police Station, Azizul Haque. Mr. Haque also said that 104 people were wounded by the explosions.