Quetta bombing: Relatives begin to bury victims
Shia Muslims in the Pakistani city of Quetta have begun burying victims of Saturday's bomb attack.
Relatives had refused to bury those killed in the attack for three days in protest at official inaction.
The burials were marked by a tense atmosphere as both security forces and officials reportedly fired shots into the air. No one was injured.
Almost 90 people were killed in the bombing, which was claimed by Sunni militant group Lashkar-e-Jhangvi.
More than 160 people were injured in the blast, which targeted an area populated by Hazaras, an ethnic group who practise Shia Islam.
Some protesters present at the burials said the victims should not be interred until the army agrees to intervene in Quetta, reports say.
On Tuesday, Pakistani police said they had arrested 170 suspects over the attack.
Security sources said police killed four people, including a bomb-maker accused of anti-Shia attacks.
The authorities have previously been accused of turning a blind eye to the killing of members of the Shia minority.
Prime Minister Raja Pervez Ashraf has ordered an operation aimed at "eliminating those responsible for playing with innocent lives", although he has not released further details.
But some wonder if there will be sustained action against hard-line Sunni militant groups which were supported by Pakistan's intelligence agencies in the past, correspondents say.
Shia Muslims are furious at what they see as a lack of protection from local and national forces in the face of repeated attacks.
Strikes and protests took place in several Pakistani cities after Saturday's bombing, including in the commercial capital, Karachi.
In January bombers targeted a snooker hall in the city, killing some 90 people, sparking a similar protest by relatives of those killed.
Another bomb at a Shia mosque earlier in February killed 24 people, raising the Shia death toll to more than 200 in less than two months, according to reports.
BBC Afghan's Imran Ali says the inaction has come as no surprise to the Hazara community, and frequent targeted killings and bomb explosions in Quetta mean many Hazaras are living in a state of fear.
Many are apprehensive to leave their homes and those who work in areas that are deemed dangerous are told by their employers to stay at home, our reporter adds.
Quetta is the capital of Balochistan province, which borders Iran and Afghanistan, and has been plagued by a separatist rebellion as well as sectarian violence.
Hundreds of Shia Hazaras in Quetta have been killed in attacks over the past few years.