Three Afghans armed with pistols and hand grenades hijacked a school bus to Islamabad from the northwestern Pakistani town of Peshawar on Sunday, taking 73 schoolchildren and staff hostage, officials and witnesses said.
The masked gunmen, who later released all but 16 Pakistani schoolboys, said they wanted $5 million, officials said.
Earlier, the gunmen said they would free the boys, ages 12 to 14, only after food supplies were delivered to the beleaguered Afghan capital, Kabul.
"We want guarantees that food has reached and been distributed equally among the people of Kabul," one of the gunmen said, outlining their demands in an interview with a reporter of the British Broadcasting Corp.
"We are not enemies of the children, and when we are sure supplies have gone to Kabul we will release them," the gunman said.
The Afghans allowed the bus to be moved from its initial position outside the Parliament building and entered the Afghan Embassy with their hostages after negotiations began with Pakistani Interior Minister Nasirullah Babar.
Babar said he had offered to meet their demands for food to war-shattered Kabul and a safe passage back to Afghanistan but had refused a ransom demand.
He said the gunmen had asked for 2,000 truckloads of food for Kabul, where 900 people have been killed and 10,500 injured in bloody battles for power between President Burhanuddin Rabbani and Prime Minister Gulbuddin Hekmatyar since Jan. 1.
"We said we will give you more, and we will give you medicines also if you want," Babar said. "I will ensure your safe passage and take you by helicopter anywhere you want in Afghanistan."
Hundreds of police cordoned off the embassy and the orange bus that was hijacked in Peshawar, 100 miles from Islamabad, as it was picking up children to take them to school early Sunday.