Bulgaria and the Philippines insisted Friday they would not be cowed by terrorists after insurgents captured and threatened to kill their nationals in Iraq, the latest hostage takings in the country.

In what has become familiar imagery, video broadcast earlier in the day on Al-Jazeera showed two Bulgarians before three masked men, two carrying rifles and one carrying a rocket propelled grenade launcher. A videotape of the Filipino was shown Wednesday, also on Al-Jazeera.

A group loyal to insurgency leader Abu Musab al-Zarqawi (search) threatened to kill the Bulgarians if the U.S. military did not release all Iraqi detainees within 24 hours — a deadline that expired Friday. The Philippines was told to withdraw its troops within three days, a deadline that expires over the weekend.

Elsewhere, the U.S. military command said Friday an American soldier died from wounds sustained in an insurgent attack on his patrol.

The soldier was wounded in the Thursday night attack in Baghdad and taken to a combat hospital, where he later died, the military said.

U.S. forces detained two people in the attack.

Philippines Vice President Noli de Castro said the government "will not be cowed and be blackmailed by acts of terrorism." A day before, President Gloria Macapagal Arroyo (search) had barred government labor agencies from sending contract workers to Iraq.

In the Bulgarian capital, Sofia, Foreign Minister Solomon Pasi said Bulgarian and U.S. officials were in contact and that "Bulgaria's foreign policy is clear and predictable and there is no way to change it because of one or another group."

Bulgaria "will do everything possible to defend its nationals," he said, without elaborating. Defense Minister Nikolai Svinarov said the captors' deadline had expired and that Bulgaria would ask them to extend it.

The kidnappings were yet another bid to pressure the United States' coalition allies. Al-Zarqawi's Tawhid and Jihad group claimed responsibility for the beheading of U.S. businessman Nicholas Berg (search) and South Korean translator Kim Sun-il (search).

It was also believed to be behind a series of attacks on police and security forces in Iraq that killed 100 people in the days leading up to the coalition forces' handover of power to an Iraqi interim government last month.

Also Friday, Pakistan announced that Iraqi insurgents freed a Pakistani hostage they had threatened to behead unless Islamabad closed its embassy in Iraq and ordered all its citizens home.

An editor at Al-Jazeera's newsroom in Doha said the channel received the tape of the Bulgarians Thursday. The Bulgarian Foreign Ministry confirmed the kidnappings, identifying the two men as truck drivers Ivaylo Kepov and Georgi Lazov.

They were kidnapped as they were en route to the Iraqi city of Mosul, coming from Bulgaria via Turkey and Syria, the Foreign Ministry said. Their schedule put them in Mosul on June 29, the last day that either of the men contacted their families back home.

The videotape of the Filipino showed three armed and masked men stood behind the seated hostage, threatening to kill him if the Philippines doesn't withdraw its troops out within three days.

Philippine authorities identified him as Angelo dela Cruz, 46, a truck driver and father of eight from the town of Mexico in northern Pampanga province.

Dela Cruz's family met with Arroyo and appealed to him to agree to the kidnappers' demands and withdraw a tiny contingent of peacekeepers to spare his life.

"Help us," dela Cruz's 24-year-old son, Julisis, tearfully said on Philippine radio. "Please bring him home alive so that we can all be together again. Please make a decision on their demand. Please pull out. We want to see him alive."

Only 51 Philippines soldiers and police are part of the nearly 160,000-strong multinational force; their deployment is scheduled to end later this month and Manila has been considering whether to extend their tour of duty.

It is the 4,100 Filipino contractors working on U.S. military bases who have become so crucial to day-to-day functioning, providing food services, janitorial work and building maintenance.

The U.S. military, which has diverted as many soldiers to combat duty as possible, would be hard pressed to operate in Iraq without the extra manpower the Filipinos provide.

Earlier this year, three Filipino workers were killed in attacks by Iraqi insurgents.

Bulgaria has a 480-member infantry unit in Iraq, under Polish command in the city of Karbala in central Iraq. Its main duties are patrolling the center of the city and guarding public buildings.

Bulgaria lost five soldiers in a suicide attack against its base in December. In April, a sixth Bulgarian was killed in a skirmish with insurgents.