A suicide bomb ripped through an outdoor Pakistani market on Friday, killing at least 18 people, half of them ethnic Hazaras, officials said, in an attack apparently aimed at minority Shi'ite Muslims.
Some 48 people were wounded in the blast in the southwestern city of Quetta, capital of resource-rich Baluchistan province, officials said.
Baluchistan is the focus of the $57-billion China Pakistan Economic Corridor, a transport and energy link planned between western China and Pakistan's southern deepwater port of Gwadar.
The attack came after a lull of at least a year in violence against the mainly Shi'ite Hazara minority in the province, though there have been isolated shootings.
The blast took place at Hazar Ganji, a fruit and vegetable market on the outskirts of Quetta.
Eight of the dead belong to the Hazara community, Quetta city police chief Abdul Razzaq Cheema said, adding that one paramilitary official from a squad deployed to guard the community at the market was also killed.
He initially said that the explosive device was hidden between sacks of potatoes, but, later, he and the provincial home minister, Zia Langove, told a news conference that a suicide bomber exploded his device among the people in the market.
"The bomber seemed to be disguised as one of the labourers when he exploded his device," another police official, Bahram Mandokhel, told Reuters. "We have found his head and other body parts."
No group immediately claimed responsibility.
Hazaras have been frequently targeted by Taliban and Islamic State militants and other Sunni Muslim militant groups in both Pakistan and Afghanistan. They have been heavily targeted in Afghanistan in attacks claimed by an affiliate of Islamic State.
Friday's bloodshed came two days after authorities freed Ramzan Mengal, a top leader of a banned sectarian group, Lashkar-e-Jhangvi (LeJ), Cheema said.
Mengal had been detained for three months under maintenance of public order regulations, he said.
The LeJ has worked both with al Qaeda and Islamic State in Pakistan and has claimed several coordinated attacks in Baluchistan against what it terms Shi'ite heretics.
Ethnic Baluch separatists are also battling what they call unfair exploitation of the province's gas and other resources.
In 2013, three bombings killed more than 200 people in Hazara neighbourhoods, prompting security forces to escort Hazara buses to the market. The same practice was followed on Friday, but the blast took place in the market.
"Targeted for their religion by sectarian armed groups, (Hazaras) have suffered many such tragedies over several years. Each time there are promises that more will be done to protect them, and each time those promises have failed to materialise,"
Omar Waraich, an official of rights group Amnesty International, said in a statement.
"Prime Minister Imran Khan's government has made important commitments to protect all religious groups. Those commitments must translate now into policies to effectively protect the Hazaras of Quetta, ending more than a decade of bloodshed."
Khan himself "strongly condemned" the attack.
"I have asked for an immediate inquiry & increased security for the ppl," he said in a Tweet.