The Pakistani city of Karachi is in mourning after a bomb killed at least 45 people in a Shia area on Sunday night. Schools and businesses are now closed by a strike.
No group has yet said it planted the bomb, which went off near a mosque in Abbas Town as worshippers left evening prayers.
Shias are the target of frequent sectarian attacks by Sunni groups.
The explosion destroyed several buildings and caused a power cut in part of the city.
Police say at least 150 people were wounded by the blast.
A strike was called on Monday in several cities across Sindh province.
The BBC reports public transport stayed off the roads and petrol pumps and filling stations were also closed. Three days of mourning have also been announced by Shia groups.
Karachi is Pakistan's biggest city and commercial capital. It has a long history of violence.