Pakistan mosque bomb blast kills 13 worshippers
President Pervez Musharraf condemned the blast as a "heinous act of terrorism" and ordered an immediate investigation.
The attack, inside a government-run religious school, shattered windows and pockmarked the walls with shrapnel and splattered blood. Bits of flesh and pools of blood lay all around as rescue workers tended to the wounded.
The school, which houses students aged four to 18, has separate mosques for Sunni and Shi'ite Muslim worshippers. Most of the victims were adults who came to the mosque for prayers.
Dr Razar Ali said 12 dead and 215 wounded were taken to Karachi's Civil Hospital, and 215 wounded. Around 45 of the injured worshippers were admitted. Most of the rest were released after treatment for minor injuries or transferred to other hospitals.
Another body and five more injured victims were taken to another hospital.
After the blast, victims lay on a hospital floor, bleeding and dazed as medics attended to them. Muslim clerics appealed for blood from mosque loudspeakers throughout the city.
Sadir Durrani, a police explosives expert at the site of the blast at the Sindh Madrassah tul Islam school, said he had found no timing or radio devices, indicating it may have been caused by a suicide bomber.
One of the men injured in the blast described the devastation.
"I was inside the mosque for Friday prayers when a bomb exploded with a huge bang," said 23-year-old Kalb e-Abbas. "Something hit my arm and I saw blood all over my body."
Aftab Sheikh, a senior politician responsible for law and order in the Sindh province, which includes Karachi, blamed anti-state elements for the blast, but would not elaborate.
Sheikh added the attack was carried out by people who were behind other terrorist attacks in Karachi.
Karachi, Pakistan's business hub and largest city, has been hit by frequent acts of terrorism and sectarian violence. Police have been on alert in the city since April, when they found weapons and explosives in a raid on a building.
Around 80% of Pakistan's 150 million people are Sunni and most of the rest are Shi'ite. Most live together in peace, but radical groups on both sides are responsible for frequent deadly attacks.
Mirza Yousuf Hussein, a local Shi'ite leader, claimed terrorists based in a tribal region near the border with Afghanistan were behind the blast. He blamed the government for giving an amnesty after a military operation there in March.




