Story highlights A Taliban splinter group claims responsibility

The incident took place outside a gate used by women

(CNN) A bombing at a Shiite mosque in Pakistan's tribal region on Friday killed at least 22 people and injured dozens more, officials told CNN.

The explosion rocked Parachinar. The city is the capital of Kurram Agency -- a district in the federally administered tribal areas in northwestern Pakistan.

The Kurram region has endured many militant attacks because it borders war-torn Afghanistan.

Jamat Ul Ahrar, a Pakistan Taliban splinter group, claimed responsibility for the attack, in a statement sent via text to media.

At least 57 people were injured, a local health official said.

Read More