Shi'ite leader challenges Pakistan army chief over attacks
Earlier on Thursday, a separate bomb killed 11 people in Quetta's main market.
The United Baloch Army claimed responsibility for that blast. The group is one of several fighting for independence for Baluchistan, an arid, impoverished region with substantial gas, copper and gold reserves.
Baluchistan constitutes just less than half of Pakistan's territory and is home to about 8 million of the total population of 180 million.
In another attack on Thursday, in Mingora, the largest city in the Swat valley in the northwest, at least 22 people were killed when an explosion targeted a public gathering of residents who had come to listen to a religious leader.
No one claimed responsibility for that bombing. Swat has been under army rule since a military offensive ejected Pakistani Taliban militants in 2009.
The LeJ has had historically close ties to elements in the security forces, who see the group as an ally in any potential war with neighboring India. Security forces deny such links.
In a measure of the outrage, several Pakistani social media users posted Facebook comments urging the U.S. to expand its covert program of drone warfare beyond Taliban strongholds on the Afghan border to target LeJ leaders in Baluchistan.
Among the dead in Quetta was Khudi Ali, a young activist who often wore a T-shirt with fake bloodstains during protests against the rising violence against Shi'ites.
Ali's Twitter profile said: "I am born to fight for human rights and peace."
(Additional reporting by Mehreen Zahra-Malik and Katharine Houreld in Islamabad, and Matthew Green in Lahore; Writing by Katharine Houreld; Editing by Louise Ireland)
© Thomson Reuters 2014 All rights reserved.