A spokesman for Lashkar-e-Jhangvi, a Sunni group, claimed responsibility for the bomb in Quetta, which caused casualties in the town's main bazaar, a school and a computer centre. Police said most of the victims were Shi'ites. Burned school bags and books were strewn around.
Sixty-four people including school children died on Saturday in a bomb attack carried out by extremists from Pakistan's Sunni Muslim majority, police said.
"The explosion was caused by an improvised explosive device fitted to a motorcycle," said Wazir Khan Nasir, deputy inspector general of police in Quetta.
"This is a continuation of terrorism against Shi'ites."
"I saw many bodies of women and children," said an eyewitness at a hospital. "At least a dozen people were burned to death by the blast."
Pakistan's law enforcement officials say Lashkar-e-Jhangvi has become a formidable force.
More top news
Presenter Sue Perkins took the Culture Secretary to task over BBC cuts after ambushing him as he ate his dinner.
War veteran Paul Royle died at a Perth hospital on Sunday following surgery on a hip fracture.
So-called Corbynmania has officially reached ridiculous new heights - someone has bought a paper coffee cup used by Jeremy Corbyn for £51.