A powerful blast apparently targeting the Shia Hazara ethnic minority went off at a crowded fruit market.
Body parts littered the scene and injured people screamed for help as black smoke cloaked the market after the explosion.
No group has claimed responsibility for the attack, but Balochistan – which borders Afghanistan and Iran – is Pakistan’s largest and poorest province, rife with ethnic, sectarian and separatist insurgencies.
Provincial police chief Mohsin Butt said eight Hazara were among the 16 victims.
They are so frequently targeted that they are forced to live in two protected enclaves in the city and are given a daily police escort to the market to stock up on supplies.
Police chief Butt said the same had happened Friday.
The bomb detonated near a site where produce was being loaded for distribution around the market.
“I was loading a small truck and I heard a huge bang and it seemed as if the earth beneath me had shaken and I fell down,” said Irfan Khan, a labourer, from his hospital bed.
“The atmosphere was filled with black smoke and I could not see anything, I could hear people screaming for help and I was also screaming for help.”
He said the air was “filled with the stinging smell of burnt human flesh”.
Senior police official Abdul Razaq Cheema said the blast targeted the Hazarganji neighbourhood of Quetta.
Hazara make up roughly 500,000 of the city’s 2.3 million people.