ISLAMABAD, Pakistan — A suicide bomber riding a motorcycle rammed into a military truck near a busy bus station in southwestern Pakistan, killing at least 15 people, including eight soldiers, and wounding at least 40 others, military officials said on Sunday.

The Islamic State group claimed responsibility for the attack on Saturday in Quetta, the capital of Baluchistan Province in the southwest. A military spokesman said the attack had been aimed at sabotaging Independence Day celebrations, as Pakistan will mark its 70th anniversary on Monday.