A group linked to al-Qaida threatened in a videotape Saturday to behead two Americans and a Briton within two days, and insurgents carried out a new string of car bombings, killing at least 20 Iraqis and two American soldiers.
The unrelenting violence has taken 300 lives in the past week.
The videotape was the first word on the fate of Americans Jack Hensley and Eugene Armstrong and Briton Kenneth Bigley since the three construction workers were kidnapped from their Baghdad home two days earlier.
"My job consists of installing and furnishing camps at Taji base," each man said in turn after identifying himself, as all three sat on the floor, blindfolded, slightly bowed but apparently unharmed. At one point, a militant's rifle pointed down at the head of the man who identified himself as Hensley.
The Tawhid and Jihad group, led by Jordanian militant Abu Musab al-Zarqawi, claimed responsibility for the abduction and demanded the release of Iraqi women detained in two American prisons.
The videotape was broadcast by Al-Jazeera shortly before it revealed a fresh kidnapping claim. Another group claimed it had kidnapped 10 employees of an American-Turkish company and threatened to kill them in three days if the company didn't leave Iraq.
Kidnappings and spectacular bombings have become the signature weapons of insurgents waging a 17-month campaign against U.S. and Iraqi forces, a campaign that has persisted since the interim government of Prime Minister Ayad Allawi took power in June.
Nevertheless, Allawi insisted U.S. and Iraqi forces were winning the fight and said progress would be made to calm the violence before crucial elections set for January.
The insurgency is "not getting stronger; it's getting more desperate. We are squeezing out the insurgency," Allawi said, speaking in an interview to be aired today on ABC's This Week.
"We are winning. We will continue to win. And we are going to prevail," he said.
Guerrillas have struck with increasing sophistication in Baghdad, the center of Allawi's authority, and have dealt punishing blows against Iraq's security forces, which are the lynchpin of the U.S.-Iraqi strategy for fighting the insurgency.
On the road to Baghdad's airport Saturday, insurgents set off a car bomb near an overpass as a U.S. convoy passed, wounding three U.S. soldiers. When other American troops moved to the scene, another car bomb exploded, killing two soldiers and wounding eight.
In the northern city of Kirkuk, a car sped at a crowd of would-be recruits lined up at the offices of the Iraqi National Guard. Guardsmen fired on the vehicle and it exploded, leaving the street strewn with bloodied bodies, twisted metal and shards of glass.
At least 19 people were killed and 67 wounded, the Health Ministry said.
It was the third bombing in the past week targeting the beleaguered security forces, seen as collaborators with the United States and its allies.
The attack occurred as recruits lined up to read the lists of those who had passed the physical fitness test, said Rustem Abdellah, one of the job-seekers, who suffered burns to his face and chest.
"I am a graduate from the oil institute," Abdellah, 33, said from his hospital bed. "But there are no jobs available in the oil sector, and I was forced to join the guard force because of the difficult economic situation."
The hostage videotape showed the American and British captives aired in part on Al-Jazeera television before it was posted in full on a Web site known for carrying Islamic militant material.
In the tape, a masked militant dressed in black stood behind the men and read from a statement, saying the three were kidnapped because they offer logistic support to American troops. He threatened to kill them unless Iraqi women detained at the American-controlled Abu Ghraib and Umm Qasr prisons are freed within 48 hours.
A U.S. military official said only two Iraqi women were in U.S. custody.
The militant accused Allawi of enabling "infidel foreigners" to "violate the honor of Muslim women, humiliate people and suck up the riches of the country" and gave the United States and Britain 48 hours to release Iraqi women detained at Baghdad's Abu Ghraib prison and Camp Bucca at Umm Qasr in the British-controlled south.
If the demand is not met, the speaker warned: "By the name of God, these three hostages will get nothing from us except their throats slit and necks chopped, so they will serve as an example."
In Armstrong's home town of Hillsdale, Mich., his brother, Frank Armstrong, said he'd spoken with the FBI about the abduction but declined to comment.
"We only know what they're showing on television," said Minnta Davis, Armstrong's cousin. "We just know there are just a lot of prayers for him."
Gulf Supplies and Commercial Services, the employer of the kidnapped Americans and Briton, refused to comment on the tape.
Both the prison facilities named in the video are run by American forces. Abu Ghraib is the prison where U.S. soldiers were photographed sexually humiliating male prisoners. Fears about the safety of female inmates have multiplied since then.
Lt. Col. Barry Johnson said coalition forces do not hold women at Abu Ghraib or at Camp Bucca.
"The only females we hold are two high-value detainees, which are kept with the other approximately 100 high-value detainees in a separate, secure location," Johnson said.
He did not rule out the possibility that women were among an estimated 1,500 prisoners at an Iraqi facility for convicted criminals at Umm Qasr.
Justice Ministry official Nouri Abdul Raheem said a U.S.-Iraqi committee reviewing the cases of detainees had decided to release all women and juveniles within the next two weeks.
IRAQI AIRWAYS TAKES OFF: The country's state airline made its first international flight Saturday since sanctions were imposed on Saddam Hussein's regime in 1990. The rented Boeing 737 above landed in Damascus, Syria. The airline will have one flight daily to Damascus and Amman, Jordan. A route to the United Arab Emirates will be added later. Round-trip fare between Amman and Baghdad is $750.