QUETTA, Pakistan: The death toll from a suicide bombing at a mosque in the southwestern Pakistani city of Quetta rose to 15 on Saturday, officials said.
The blast during Friday evening prayers wounded at least 20 other people, police said.
"Two of the wounded people died overnight in the hospital," said provincial home minister Zia Langove, adding that six people were still in a critical condition.
Islamic State claimed its suicide bomber carried out the attack to target an Afghan Taliban seminary.
"The U.S. condemns this heinous terrorist attack in a place of worship," Paul Jones, the U.S. ambassador to Pakistan, said in a statement. "I extend our condolences to the families of those who lost their lives."
Mineral and gas-rich Baluchistan, of which Quetta is the capital, is at the centre of the $60 billion China-Pakistan Economic Corridor, part of China's Belt and Road project.
But violence in the province has fuelled concerns about the security of projects such as a planned energy link from western China to Pakistan's southern port of Gwadar.
The attack was the second in the city this week, while police said they had foiled another by killing a suicide attacker in Rawalpindi city near Islamabad after he shot and killed two policemen.