Associated Press
Two bombs targeting Shia Muslims exploded in Pakistan's largest city today, one outside a hospital treating victims from the first blast hours earlier. At least 22 people were killed and more than 50 others wounded.
Police appealed for calm following the strikes in the chaotic city of 16 million people. Karachi has a history of religious violence between Shiite and Sunni Muslims, and has been tense in recent weeks due to deadly clashes between rival political parties.
In late December, a bomb in the southern port city killed 44 Shiites attending a procession to mark Ashura, the anniversary of the death of revered Shiite figure Imam Hussein, sparking deadly riots. Friday's blasts coincided with Arbaeen, the final day of the annual 40-day mourning period for Hussein.
One of Pakistan's many al-Qa'ida linked Sunni extremist groups will be suspected in the twin attacks.
The first blast targeted a bus carrying worshippers, most of them women and children, killing 12 and wounding 49, officials said. The bomb was attached to a motorcycle and detonated as the bus drove to an Arbaeen procession, witnesses said. One witness said it may have been a suicide bombing, but that could not be confirmed.
The second bomb exploded outside the entrance to the emergency ward at Jinnah Hospital, which was packed with victims and relatives of those killed and wounded in the earlier attack. It was either hidden on a motorbike or in or close to an ambulance, a witness and a government official said.
Government spokesman Jamil Soomro said 10 people were killed and several others were wounded.
Shiites were also attacked in Iraq on Friday as they attended Arbaeen commemorations.
A suicide attacker detonated a car bomb alongside a crowd of Shiite pilgrims walking to a holy city south of Baghdad, killing at least 27 people and wounding 70. It was the third deadly bombing this week against Shiites converging on the holy city of Karbala, where Imam Hussein was killed in battle in 632.
In Karachi, Ashfaq Ali survived the bus attack, but lost two sons. He sat on the floor near a pool of blood.
"I will keep sitting here because it is my sons' blood," he said, half-wailing. "I want the terrorists to kill me as well."
Pakistan's Sunnis and minority Shiites generally live in peace, but extremists from the two sects have targeted one another's leaders and worshippers. Al-Qaida and the Taliban are Sunni extremist groups and also despise Shiites, believing them to be infidels.
The Pakistani Taliban, whose stronghold is in the northwestern mountains far from Karachi, have staged a string of bombings in recent months against government, security forces and Western targets, but not Shiite ones. The bombings, which have killed hundreds of people, follow a major Pakistan army offensive against the militants near the Afghan border.
Two bombings in Karachi, Pakistan have killed at least twenty-two people and injured over fifty. 

Karachi, Pakistan 
In spite of tight security across Pakistan, a motorbike carrying explosives was able to hit a bus carrying people to a religious procession, killing twelve. A second bomb killed at least thirteen when it exploded an hour later outside the local Jinnah hospital emergency ward where the victims, mainly Shia Muslims, of the first attack were being treated. 

The bus attack took place on a shopping street near the main road that connects the airport with the city, but it is not clear whether it was a suicide bomber ramming the vehicle, or whether the motorbike was parked along side the bus before detonation. 

The second bombing by the hospital, which struck within a crowd of protesters that had gathered to mourn the people killed in the first attack, was likely a suicide bombing, according to local police.

Ghylam Nabi, a local police officer, told Reuters that a third bomb had been found inside a television set in the hospital premises. It was defused successfully.

40 Shia Muslims were also killed in a car bomb attack today in Karbala, Iraq, as they took part in the final day of the religious festival known as Arbaeen, the 40 day mourning for the grandson of the Prophet Muhammed. This was the third bombing in Karbala this week.