A bomb exploded at a Shiite Muslim (search) mosque packed with worshippers in this southern Pakistani port city Friday, killing 14 people and wounding more than 200 others in a suspected homicide attack, police and witnesses said.

President Gen. Pervez Musharraf (search) condemned the blast as a "heinous act of terrorism" and ordered an investigation.

The attack occurred shortly after 1 p.m. at a mosque inside a government-run religious school, shattering windows and peppering the walls with shrapnel. The wounded lay screaming for help on bloodstained carpets in the mosque while dazed worshippers stumbled out.

The Sindh Madrassah tul Islam school, which houses students ages 4-18, has separate mosques for Sunni (search) and Shiite Muslim faithful. Witnesses said the school had let out early, as usual on Friday. Most of the victims were adults who came to the mosque for prayers.

The bombing triggered unrest in Karachi, Pakistan's largest city and home to several radical Islamic groups. Hundreds of Shiite youths burned cars, gas pumps and a government office in the city, which has been hit by frequent acts of terrorism and sectarian violence.

There was no word on the motive for Friday's attack.

Tariq Jamin, deputy inspector-general of Karachi police, said 14 people were killed in the bombing and more than 100 were injured.

But Dr. Razar Ali said 215 wounded were brought to Karachi's Civil Hospital, and 45 were still hospitalized. Most of the others were either released after treatment or transferred elsewhere.

Sadir Durrani, a police explosives expert, said he had found no timing or radio devices, indicating the attack may have been the work of a suicide bomber.

Chief investigator Manzoor Mughal said no crater was found at the blast point, suggesting a person was carrying the bomb. Several injured people described a man in a black robe and black turban who was sitting near the column where the bomb exploded.

"We are still investigating, but it seems it was a suicide bombing," Mughal said.

Kalb e-Abbas, 23, told The Associated Press he was in the mosque for Friday prayers when he heard "a big bang."

"Something hit my arm, and I saw blood all over my body," he said, adding that he could hear the cries of the wounded around him before stumbling out of the building.

Aftab Sheikh, a senior politician responsible for law and order in Sindh province, where Karachi is located, blamed anti-state elements for what he called "a barbaric act."

"Today's bomb attack was carried out by those people who were behind other terrorist attacks in Karachi," Sheikh said without elaborating.

Muslim clerics appealed for blood from mosque loudspeakers throughout the city.

The provincial government announced it would give $1,750 compensation to families of the dead, and $525 to each of the injured.

Police have been on alert in Karachi since April, when they found weapons and explosives in a raid on a building. It was unclear whether the mosque attack was linked to that raid.

About 80 percent of Pakistan's 150 million people are Sunni, and the rest Shiite. Most live together in peace, but radical groups on both sides are responsible for frequent deadly attacks.

In March, Sunni radicals attacked a procession in the southwestern city of Quetta, killing more than 40 people and wounding 150.

Another bomb attack in Quetta injured two people Friday, a day before Prime Minister Zafarullah Khan Jamali was scheduled to inaugurate an international investment conference at a nearby hotel.