The Shiites responded by burning shops and cars while clashing with police in Hangu, about 200 kilometers (125 miles) southwest of the capital, Islamabad, said a senior Interior Ministry official, who asked not to be named because he's not authorized to speak to the media.
The explosion hit the procession of hundreds of people in a bazaar soon after it emerged from the main Shiite mosque, the official said. It wasn't clear if the bomb was detonated by a timer or a suicide attacker, said the official in Islamabad.
"The situation is very grave there. People are fighting. Police are trying to control them. Our priority is to get the injured to hospital, but angry and emotional processionists are attacking police vehicles and even ambulances," the official said.
The attack targeted Shiites observing Ashoura, the most revered religious holiday in their faith. The event marks the 7th century death of Imam Hussain, a grandson of the Prophet Muhammad. Hussain's death led to a rivalry between Shiites and Sunnis over who should succeed the prophet.
Security was tight for holiday because it has been marred by violence in recent years. Sunni Muslims, the majority in Pakistan, have been blamed for attacking the Shiites during the event, which involves religious processions across the country, reports the AP.
Biden built a near-half century political career on a foundation of Big Lies and mass deception. They'll surely continue as long as he remains in office.