Parts of Karachi saw protests today over the bomb blast yesterday in a central imambargah (a Shia congregation hall) in Sindh province's Shikarpur that left at least 60 people dead, Dawn reported.
A sit-in was staged on the call of Majlis Wahdat-i-Muslimeen (MWM), by a large number of men, women and children at the Numaish traffic intersection.
According to the protesters the terrorists were roaming about freely and the government had failed to protect citizens' lives.
Sit-ins were also staged in various other Shia localities.
The strike call was supported by the Sunni Ittehad Coucil, Sunni Alliance, Pakistan Muslim League (Quaid), Pakistan Awami Tehreek.
The Sindh government, Muttahida Qaumi Movement and traders' alliance expressed 'solidarity' with the victim families.
The Sindh government also announced a day of mourning in solidarity with the families of the victims and announced that the national flag would fly at half mast today. Compensation was also announced for the victims' families.
Meanwhile, Pakistan's Daily Times reported that the police said the blast was caused either by a suicide bomber or an explosive device that went off when the mosque was full to capacity last afternoon in the centre of Shikarpur, Sindh.
According to Shikarpur police chief Saqib Ismail Memon, the police was trying to ascertain the nature of the blast and a bomb disposal squad was examining the scene.
There were chaotic scenes at the blast site as, part of the mosque collapsed after the explosion, burying some of the wounded under rubble.
Bystanders extricated those trapped under the debris and rushed them to hospitals.
A splinter group of Pakistan Taliban, Jundullah, which pledged support last year to the Islamic State group based in Syria and Iraq, claimed responsibility.
Fahad Marwat, a Jundullah spokesman said the group's target was the Shia mosque, as they were ''our enemies.''