Three kidnapped U.N. election workers appeared frightened but otherwise well in a videotape aired Sunday on the al-Jazeera satellite television network. Their kidnappers, in telephone calls to news agencies, threatened to kill the hostages in 72 hours unless U.N. and foreign troops withdrew from Afghanistan, and Taliban and al Qaeda prisoners were freed from U.S. military jails.

The three hostages -- Annetta Flanigan of Northern Ireland, Shqipe Habibi of Kosovo and Angelito Nayan, a Philippine diplomat -- were shown huddled together and sitting cross-legged on a floor.

The three were abducted on Thursday afternoon by several men in military uniforms brandishing AK-47 assault rifles, in the first such abduction of foreigners in Kabul since an American bombing campaign drove the Taliban from power nearly three years ago.

The kidnappings prompted a massive security review for the estimated 2,000 Westerners here, as fears mounted that the abductions could presage a deadly new phase in the ongoing, low-level insurgency that has included suicide bombings in the capital and roadside bombs and ambushes in the southern and eastern regions of the country.

Jaish-e-Muslimeen, or Army of Muslims, a splinter group of the ousted Taliban government, issued a set of four demands in telephone calls to various news agencies. The group called for the United Nations to cease operations in Afghanistan and condemn the "attacks and invasion of Afghanistan by foreign forces." It also demanded that the United States free all prisoners held at its detention facility at Guantanamo Bay, Cuba, and U.S. prisons in Afghanistan.

The group also appealed directly to the home countries of the hostages. A spokesman said one demand was that Britain and Kosovo "withdraw their forces immediately" from Afghanistan -- even though Kosovo, a province of Serbia currently under U.N. protection, has no troops in the country. In its final demand, Jaish-e-Muslimeen said the Philippine government must "condemn the invasion of foreign forces in Afghanistan."

The demands were issued separately by a spokesman for Jaish-e-Muslimeen, Mohammed Ishaq, who contacted the French news service Agence France-Presse, and by a commander of the group, Sayed Mohammed Akbar Agha, who telephoned the Reuters news agency.

Ishaq said that if the governments involved did not meet the group's demands, they would "witness the deaths of their nationals in three days."

The United Nations appealed for the release of the hostages, saying all three suffered unspecified ailments. "We call on those holding them not to harm them," said a U.N. spokesman, Manoel de Almeida e Silva. "All three require medical attention, and the best response to such a situation is their immediate release." He declined to give further details.

A senior official with Afghanistan's Interior Ministry, Shah Mahmoud Miakhel, in an interview confirmed that the hostages were in the hands of Jaish-e-Muslimeen but said he was "one hundred percent certain" that they had been seized initially by a criminal gang, perhaps hired by the group.

Miakhel confirmed reports that commander Akbar Agha several months ago broke away from Taliban leader Mohammad Omar because of disagreements over how best to continue the insurgency and whether to disrupt the Oct. 9 presidential election through violence. Omar, along with Osama bin Laden, is being hunted by U.S. troops in Afghanistan's mountainous regions.

Miakhel said Akbar Agha's faction is relatively small and lacked the logistical structure in Kabul to carry out the kidnappings. "He doesn't have a network."

A spokesman for Omar's Taliban faction disavowed any connection with the kidnappings. "We have no comment about the issue," the spokesman, Hamid Agha, told Reuters. "It is their work, and we are not involved in it."

U.N. workers Annetta Flanigan, left, Angelito Nayan and Shqipe Habibi, who are being held hostage in Afghanistan, are seen in this video aired on the al-Jazeera satellite television network.