ISLAMABAD, Pakistan — In a deadly sectarian attack, at least 54 people were killed Friday evening and about 75 wounded when two bombs ripped through a town in a tribal region of northwestern Pakistan, officials said. A militant group affiliated with the Pakistani Taliban claimed responsibility.

Most of the dead in Parachinar, the main town of the Kurram tribal region near Afghanistan, were believed to be Shiite Muslims.

Kurram, a remote tribal region of rice paddies and fruit orchards, has long simmered with sectarian tensions, and its predominantly Shiite population has come under repeated attacks by Sunni Taliban militants.

In 2009, the Taliban blocked all routes from Kurram leading to the rest of Pakistan, and Shiites had to go through Afghanistan to make their way to Peshawar and other Pakistani cities. The road is now open, but despite a number of government military operations, the situation remains grim for Shiites in Kurram and elsewhere in Pakistan as extremist Sunni militants have targeted them in a vicious cycle of violence.