Families of Quetta blast victims search for answers
22 February 2013 Last updated at 22:35 GMT
Pakistani police say they have arrested 170 suspects after a bomb attack last Saturday which targeted a Shia Muslim area in the western city of Quetta.
Security sources said police killed four people, including a bomb-maker accused of anti-Shia attacks.
Last Saturday's bomb ripped through a busy market district, killing almost 90 people and injuring some 169 more.
Orla Guerin reports.