Authorities in Pakistan say a suicide bomber has killed at least 15 people and injured more than 22 others in a central part of the country's capital city.  Most of the victims were policemen.  Ayaz Gul reports from Islamabad.

Aftermath of the Islamabad suicide bombing, 06 Jul 2008

The suicide bomber struck a group of policemen who were guarding a big meeting of Islamic activists in the center of the Pakistani capital.

The religious gathering was marking the one-year anniversary of a military crackdown on Islamabad's radical Red Mosque, just few hundred meters away.

Witnesses say most of the deaths happened instantly and body parts, pools of blood as well as police caps littered the scene.

A top official at the federal Interior Ministry, Kamal Shah, says the attack is being investigated, but he dismissed criticism poor security arrangements led to the deadly bombing

"An individual coming and exploding himself, blowing up himself is difficult to prevent," said Kamal Shah. "This has happened in other countries of the world.  It is not [happening] only in Pakistan."

Speaking at a ceremony in the southern city of Karachi hours after the blast, President Pervez Musharraf condemned it as a terrorist act.

"I condemn that with all my force and I must say that this nation has to show resolve to fight such extremism and terrorism and defeat it," said Pervez Musharraf.

Doctors have described conditions of some of those wounded in the attack as critical, saying the death toll could go up.

The suicide bombing occurred just after several-thousand participants of the religious gathering started dispersing.  The crowed had gathered to condemn the army raid on the Red Mosque complex that killed more than 100 people on July 10 last year.

Speakers at the meeting criticized President Pervez Musharraf for ordering the assault under pressure from the United States.  The protesters chanted anti-Musharraf and anti-American slogans.

Pro-Taliban militants supportive of the radical mosque unleashed a wave of deadly suicide bombings across Pakistan in the past year to avenge the operation.  Most of the victims of the violence have been security personnel.

The crackdown against the mosque was launched after its clerics and religious students ignored official warnings to end their violent campaign to enforce Taliban-style rule in parts of the Pakistani capital.  The extremists kidnapped women they accused of prostitution, including some Chinese nationals, and warned traders against running music and video shops.