QUETTA, Pakistan — A series of bombings killed 115 people across Pakistan on Thursday, including 81 who died in twin blasts on a bustling billiards hall in a Shiite area of the southwestern city of Quetta.
Pakistan’s minority Shiite Muslims have increasingly been targeted by radical Sunnis who consider them heretics, and a militant Sunni group claimed responsibility for Thursday’s deadliest attack — sending a suicide bomber into the packed pool hall and then detonating a car bomb five minutes later.

It was one of the deadliest days in recent years for a country that is no stranger to violence from radical Islamists, militant separatists and criminal gangs.

Violence has been especially intense in southwest Baluchistan province, where Quetta is the capital and the country’s largest concentration of Shiites live. Many are ethnic Hazara who migrated from neighboring Afghanistan.