At least 16 people were killed and 30 wounded in a bomb blast Friday at a fruit market in Pakistan's southwestern city of Quetta, officials told AFP.

Mohsin Butt, provincial police chief for Balochistan, gave the death toll and said eight ethnic Shia Hazaras were among the victims, along with one security official and workers from the market.

The Hazara, whose Central Asian features make them easily recognisable, are a soft target for Sunni militants who consider them heretics.

Members of the bomb disposal unit survey the site after a blast at a vegetable market in Quetta, Pakistan on April 12, 2019.Photo: Reuters

Senior police official Abdul Razaq Cheema said the blast had taken place in the Hazarganji neighbourhood of Quetta, Balochistan's capital.

An AFP reporter at the site saw human flesh and blood scattered around the site, with injured people screaming for help.

A local police official who was posted at the fruit market and survived the bomb said the area had been packed at the time of the blast early in the morning.

During the early hours trucks arrive with vegetables brought in from outside the city, to be shifted by traders into smaller vehicles and delivered throughout Quetta.

"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," one labourer in his early 20s, Irfan Khan, told AFP from a hospital in Quetta, where he was receiving treatment for minor injuries.

"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". He lost consciousness, and awoke in hospital.

His injuries include shrapnel from ball bearings and pieces of metal, "but the doctors say I should be discharged very soon", he said.

No group has yet 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.

Hazara make up roughly 500,000 of Quetta's population of 2.3 million. They are so frequently targeted that police chief Butt said the victims in Friday's blast were given police protection every time they visited the fruit market.

"The same happened today, there were police and FC (Frontier Constabulary) guarding them when the blast occurred," he said.

Police are investigating what kind of blast it was, he added.

Violence in Pakistan has dropped significantly since the country's deadliest-ever militant attack, an assault on a school in the northwestern city of Peshawar in 2014 that killed more than 150 people, most of them children.