July 7 (Bloomberg) -- Pakistan's government said it is trying to identify the suicide bomber who killed at least 19 people, mostly police officers, in an attack in the capital, Islamabad, yesterday.

A bearded man detonated a bomb he was wearing after walking into a crowd of policemen, said Interior Minister Rehman Malik. The officers were guarding a demonstration by Islamic militants and sympathizers marking the first anniversary of an army assault on Islamist guerrillas at Islamabad's Red Mosque.

The rally drew thousands of men, including members of extremist groups banned by the government, according to independent Pakistani TV news channels. While no group immediately claimed responsibility for the bombing, Dawn News television cited a spokesman for a Pakistani Taliban group, Muslim Khan, as saying it was retribution for the army assault on the mosque.

Government ministers, including Prime Minister Yousuf Raza Gilani, condemned the attack as a violation of Islam. ``It was a hopeless attempt of enemies of the country and democracy,'' the official Associated Press of Pakistan cited Information Minister Sherry Rehman as saying yesterday in Islamabad.

Malik told reporters the authorities recovered the upper part of the bomber's body. The government is offering a 5 million rupee ($72,000) reward for information that leads to the arrest of the plotters, he said.

Police Base

The attack occurred outside a police station a few hundred yards from the mosque, which also is known by its Urdu-language name, Lal Masjid. The bomber may have been a teenager, perhaps as young as 16, an injured police constable, Muhammad Iqbal, told Dawn News from his hospital bed.

``We heard a huge blast, and my house shook,'' said Kamran Ahmed, a resident of the neighborhood. ``We ran down to look, and there were so many policemen dead in the street.''

It was the third deadly bombing in four months in Islamabad, which until the Red Mosque siege had mostly escaped Pakistan's Islamic militant violence. ``After one year,'' the mosque has become ``a national icon which the state destroyed and now must pay for,'' said the English-language Daily Times in an editorial July 5.

Six-Month Campaign

Last year, militant students, clerics and fighters made the mosque their headquarters for a six-month campaign to enforce their vision of Islamic Sharia law. They kidnapped women they suspected of prostitution and ordered local shopkeepers to stop selling what they called ``un-Islamic'' music and videos.

After militants fought police and rioted, President Pervez Musharraf ordered the army to besiege the religious leaders and gunmen in the mosque and its attached religious school. Musharraf imposed military rule on Pakistan for eight years, ending last November, and was the army commander at the time of the 10-daylong Red Mosque siege.

After most of the school's students fled to safety, the army attacked with heavy weapons, destroying the school and killing those remaining inside. The government confirmed 100 dead in the attack, although militant sympathizers say the toll was higher.

Angry emotions over the July 2007 bloodshed were on display at yesterday's protest rally, where speakers demanded that Musharraf be tried and publicly hanged for ordering the assault. The rally represented part of a ``jihad against America'' that ``will continue until the last drop of our blood,'' declared Shah Aziz, a cleric and former member of parliament.

Terrorist Groups

Pakistani news channels said the protesters included members of Sipah-e-Sahaba and Jaish-e-Muhammad, militant groups banned by Musharraf in 2002. Jaish-e-Muhammad is on the U.S. State Department's list of international terrorist organizations.

The assault on the mosque last July prompted a wave of Taliban suicide bombings across the country that left 1,000 people dead. The violence spread from Taliban strongholds in the ethnic Pashtun region along the Afghan border in the west to include attacks on government, military and police targets across the country.

In March, a bomb exploded in Islamabad at an Italian restaurant popular with Westerners, killing a Turkish woman. On June 2, a suicide car bombing heavily damaged the Danish embassy and killed eight people.

To contact the reporter on this story: James Rupert in Islamabad at jrupert3@bloomberg.net.

Last Updated: July 6, 2008 19:58 EDT