The attack happened today in the restive southwestern province of Balochistan. At least 25 people were killed and dozens of others wounded, local officials said.
Hashim Ghalzai, a local district commissioner, told Reuters news agency the toll was based on initial reports and could rise further. The blast occurred outside Karachi, Pakistan's largest city, in Hub district.
The bombing at the remote Shah Noorani shrine took place while hundreds of people were inside. The Sufi shrine attracts a lot of people at this time of the year from other parts of Pakistan.