The Arab satellite television channel broadcast a tape showing Kim Sun-il, 33, kneeling before five masked and armed men, one of whom wore a large knife in his belt. Kim, wearing an orange prison jump suit and matching blindfold, heaved his shoulders, his mouth gaping open as if sobbing and gasping for air.
"We warned you, but you refused," one of the kidnappers said, reading from a written statement. "We had warned you, and this is what you brought upon yourselves. Enough lying and deceit. Your army is here not for the Iraqi people but for the damned America."
A few hours later, the United States launched an airstrike Tuesday in Fallujah on a safehouse used by followers of Jordanian terrorist Abu Musab al-Zarqawi — the second strike against the terror network in three days, the U.S. military said.
Al-Zarqawi's Monotheism and Jihad movement masterminded last week's beheading of American hostagein Saudi Arabia, and the May beheading of American businessman Nick Berg in Iraq. Al-Zarqawi's group also claimed responsibility for Sun-il's beheading.
In other developments:
The video as broadcast by Al-Jazeera did not show Kim being executed, and the broadcaster did not say when Kim was killed.
Brig. Gen. Mark Kimmitt, coalition deputy operations chief, said the body of an Asian male was found west of Baghdad on Tuesday evening.
"It appears that the body had been thrown from a vehicle," Kimmitt said in a statement. "The man had been beheaded, and the head was recovered with the body."
President George W. Bush condemned the beheading of a South Korean hostage as "barbaric" Tuesday and said he remained confident that South Korea would go ahead with plans to send thousands of troops to Iraq.
"The free world cannot be intimidated by the brutal actions of these barbaric people," the president said.
The grisly killing was reminiscent of the decapitation of American businessman Nicholas Berg, who was beheaded last month on a videotape posted on an Al Qaeda-linked Web site by the Monotheism and Jihad group, which claimed responsibility for Kim's death. Berg was wearing the same orange prison-style clothing as Kim.
In Saudi Arabia, American helicopter technician Paul M. Johnson Jr., 49, was kidnapped by al Qaeda militants who followed through on a threat to kill him if the kingdom did not release its al Qaeda prisoners. An al Qaeda group claiming responsibility posted an Internet message that showed photographs of Johnson's severed head.
In Seoul, South Korean Foreign Ministry spokesman Shin Bong-kil said Kim's body was found by the American military Tuesday evening between Baghdad and Fallujah, a Sunni Muslim militant stronghold west of the capital.
The South Korean Embassy in Baghdad identified the body from a picture which was sent by e-mail by the Americans, Shin said.
"It breaks our heart that we have to announce this unfortunate news," he said.
Kim, 33, worked for a South Korean company supplying the U.S. military in Iraq, according to the South Korean government. He was believed abducted several weeks ago.
After news of Kim's death broke, South Korean television showed Kim's distraught family members weeping and rocking back and forth with grief at their home in the southeastern port city of Busan.
In a videotape broadcast by Al-Jazeera late Sunday, the kidnappers set a deadline of 24 hours from sunset Sunday for the South Korean government to withdraw its troops or they would "send you the head of this Korean, and we will follow it with the heads of your other soldiers."
The Seoul government said Monday it would go ahead with plans to send 3,000 troops to Iraq despite the militants' ultimatum.
NKTS, a South Korean security firm doing business in Iraq, told the AP in Baghdad earlier Tuesday that Kim was still alive and that negotiations for his release continued after the kidnappers extended the deadline, with the company president expected to arrive in Baghdad from Seoul by Wednesday.
The South Korean consul in Iraq and Kim Chun-ho, president of Gana General Trading Co., the company that employed the victim, traveled to the site to collect the remains, said Shin, the Foreign Ministry spokesman said. Gana is a supplier to the U.S. military. The body was found 35 kilometers (22 miles) west of Baghdad, Shin said.
In Seoul, Commerce, Industry and Energy Minister Lee Hee-beom said Tuesday all South Korean businessmen in Iraq will leave by early next month following the abduction of Kim Sun-il.
Dozens of foreigners have been abducted in Iraq since an upsurge of violence in April. Most have been freed although three Americans -- one soldier and two civilian truck drivers -- remain missing after their convoy was ambushed in April.
Four Italians were kidnapped April 12 and one of them, Fabrizio Quattrocchi, was killed on a video sent to Al-Jazeera but never broadcast. U.S. special operations troops rescued the three other Italians and a Polish engineer June 8 south of Baghdad.
Most of the foreign hostages were seized in the dangerous area between Baghdad and Ramadi, located west of Fallujah, which has been an stronghold of the Sunni-based anti-American insurgency.
In April, U.S. Marines laid siege to Fallujah after four U.S. security contractors were killed and their bodies hung from a bridge across the Euphrates river. Ten Marines and hundreds of Iraqis died in the three-week siege, which ended with the Americans backing away and handing security over to an Iraqi volunteer force, which included some of the insurgents.
Since then the city has fallen under the influence of radical Sunni clerics and their Mujahedeen followers. On Saturday, a U.S. airstrike destroyed what the Americans said was a safehouse used by al-Zarqawi's followers, killing key figures of his movement.
Fallujah officials claim the dead were Iraqi civilians. The Health Ministry placed the death toll at 17.
Brig. Gen. Mark Kimmitt, the U.S-led coalition's deputy chief of operations, said Tuesday's strike against the safehouse in Fallujah involved precision weapons to "target and destroy" the safehouse and was based on "multiple confirmations of actionable intelligence."
"Wherever and whenever we find elements of the Zarqawi network, we will attack them," he said.
Large explosions rocked the restive Sunni Muslim city west of Baghdad. Ambulances raced to the area after the 10:30 p.m. blasts. Wounded and dead were being evacuated, said Iraqi Police Col. Mekky Zeidan.
U.S. officials offered no casualty figures, but Al-Jazeera television reported that three people were killed and six were wounded.