At least six people were killed and 50 wounded Friday when a bomb tore through a market in a mainly Shiite area of Pakistan's northwestern tribal belt, local officials told AFP.
Doctors said they feared the death toll would rise after the attack in Parachinar, capital of the Kurram tribal district, as television footage showed shocked bystanders and ambulances in the market.
"Six people have been killed and more than 50 injured in the blast near a Shiite mosque in Parachinar market," Moeen Begum, a surgeon at the government-run hospital, told AFP.
"The death toll may rise and we are still receiving injured people," he said.
Local administration official Shahid Ali Khan confirmed the blast had taken place near the mosque.
"Many people have been injured, I can't tell the exact number," he said.
Parachinar was also the location of the first major militant attack in Pakistan in 2017, a bomb in a different market which killed 24 people in January.
In February, a fresh wave of militant violence killed 130 people across Pakistan.
The attacks, most of which were claimed by the Islamic State group or the Pakistani Taliban, dented optimism after the country appeared to be making strong gains in its decade-and-a-half long war on militancy.
Kurram is one of Pakistan's seven semi-autonomous tribal districts which are governed according to local laws and customs.
The district is known for sectarian clashes between Sunnis and Shiites, who make up roughly 20 percent of Pakistan's population of 200 million.