KARACHI, Pakistan - The school van screeched to a halt when a motorcycle with three men roared in front of it. Two of the men leapt from the motorcycle, drew their pistols and opened fire, killing the school principal, Saeed Zafar Mehdi — the latest victim of marauding death squads killing minority Shiite Muslims in this southern port city.
As the men sprayed the van with bullets, witnesses said they heard them screaming, "Kafir (infidel), Kafir Shiite Muslim." Also killed in the attack on the eastern edge of the city was the driver of the van and a school employee who was also a Shiite.
Jamil Yusuf, of the Citizen/Police Liaison Committee, called the relentless, religiously motivated attacks an attempt to destabilize Pakistan's president, Gen. Pervez Musharraf, by radical Sunni Muslims seeking revenge for his support for the U.S.-led war on terror in neighboring Afghanistan.
"They want their revenge. Their way to get the government to stop giving support to the United States is to terrorize from within," said Yusuf.
Earlier this year Musharraf banned five militant Sunni Muslim organizations and one Shiite Muslim group. He promised to crackdown on religious schools, to monitor the curriculum, their finances and their student recruitment policies.
Since Sept. 11 when Musharraf abruptly ended Pakistan's support for Afghanistan's Taliban and promised the U.S.-led coalition unconditional cooperation in its war on terror, there has been a steady rise in religiously motivated violence.
Bombs have been planted in Shiite Muslim mosques, grenades tossed in among worshippers. Last month 14 women were killed when a bomb ripped through the Shiite Muslim mosque in which they were praying.
"We are heading toward a real battle. People are angry. They want revenge. They are angry at me because I tell them to stay calm. Maybe one day they will turn on me," said Hasan Turabi, leader of the outlawed Shiite Muslim militant group, Tehrik-e-Jafria.
"Every day we are burying our dead," he said.
At his home, protected by police and intelligence agents in plain clothes, Turabi told The Associated Press the latest surge in religious assaults is directly linked to the war in Afghanistan.
Militants from both sects have been at odds before, but the last real outbreak of sustained violence had been in 1995 and 1996, said Turabi. It began again last year.
He blames the collapse of the Taliban. He said militant Sunni Muslims, who had found refuge with the Taliban in Afghanistan, retreated to Pakistan as the Taliban's hold on Afghanistan collapsed.
Many were fugitives, implicated in massacres of Shiite Muslims. Pakistan had even asked the Taliban to return them to stand trial, but they had refused.
"I would say 70 percent of the worst killers were in Afghanistan with the Taliban and now they are all back here," said Turabi, who accused Pakistan's intelligence service of aiding them. Many of the most militant Islamists had been recruited by Pakistan's secret service to fight a proxy war in Kashmir, to try to wrest full control of the divided state away from uneasy neighbor India, which controls two-thirds of the disputed region.
Turabi says Musharraf is trying to wean his powerful spy agency away from the militants, having made major changes at the highest level, retiring men known to share the ideology of the militants.
"But it won't change quickly. Still the agency is letting these men roam free," he said.
Violence between Sunni and Shiite Muslims has flared on and off over the centuries since they split over the rightful heir to the Islamic faith following the death of their prophet Mohammed. Militant Sunni Muslims in Pakistan revile Shiite Muslims as outside the pale of Islam.
The killings of Shiite Muslim are most often in broad daylight, and on deeply congested thoroughfares.
In the Arabian Sea port city of Karachi, Pakistan's largest city of 14 million, the killings have been targeted. Gunmen have carried out execution-style killings like the one Monday. The victims have mostly been Shiite Muslim and many of them professionals.
Last month doctors in Karachi walked off the job for one day to protest the deaths of their colleagues, most of whom were Shiite Muslims gunned down as they left for work or while they sat in their clinics treating the ill.
On Sunday Dr. Athar Rizvi, 50, was shot at point-blank range in his clinic not far from the scene of Monday's shooting of the school principal. Rizvi was a Sunni Muslim but police believe his killers may have acted on the assumption that he was a Shiite Muslim because his name is common among Shiites and the neighborhood in which he practiced is dominated by Shiite Muslims.
Rizvi survived the shooting but is in critical condition in hospital.
Some people in Karachi fear the killings are an attempt to drive the educated Shiite Muslims from the city.
Yusuf said the killings are an attempt to sabotage Musharraf's economic plan, drive investor confidence down.
"This is payback for his support of America," said Yusuf.