At least one person was killed and scores injured in the Bangladesh capital on Saturday when a blast ripped through a venue where preparations for 'Ashura' celebration were taking place, an officer said.The blasts occurred at 1.30 a.m. when Shiite Muslims had gathered for a traditional procession to be taken out from the venue (Hussaini Dalan) in the morning, Xinhua reported."One youth was dead and at least 70 people were injured as three handmade grenades blasted," said a police officer.Ashura, or the 10th of Muharram in the Islamic calendar, is observed in Bangladesh to commemorate the martyrdom of Imam Hussain, grandson of Islam's Prophet Mohammed.