At least 10 people have died in an explosion outside an emergency hospital ward in Karachi where the wounded victims of an earlier suicide bomb attack were being treated.
Approximately 50 people injured in an attack on a bus full of Shia Muslims had been rushed to the Jinnah hospital in Pakistan’s commercial capital.
Then as ambulances arrived filled with the wounded another bomb exploded causing fresh casualties.
Twelve people died in the first attack believed to have been carried out by a motorcyclist.
The bus was one of many taking mourners to a ceremony commemorating the death of the grandson of the Prophet Mohammad.
The main procession was heavily guarded on all sides to prevent a repeat of an attack on a Shia march in December which killed 43 people.
But the bus attacker picked a spot well away from the security cordon.
Police say they have also defused a third bomb which had been hidden inside a television set in the hospital.
Troops have been deployed in the city to prevent clashes between rival political groups.