Iraq's Shiite interior minister accused critics Thursday of exaggerating reports of torture at a lockup seized by U.S. troops last weekend, saying inmates included both Shiites and Sunnis and only a handful showed signs of abuse.

Interior Minister Bayn Jabr suggested some making the torture allegations were supporting the insurgency or had a personal score to settle and were using the U.S. Embassy to exert pressure on him. He also said the Interior Ministry facility in the capital's Jadriyah district had held "dangerous terrorists," including one man accused of building six car bombs.

One prisoner who was suffering from polio was a Shiite hired by Sunni religious extremists — to detonate a roadside bomb, he said.

In continuing violence by insurgents, the U.S. military said Thursday a Marine was killed a day earlier during combat operations near the western Iraqi city of Haditha — one of seven American service members to die Wednesday. Six of them were Marines.

It was the deadliest day for American forces in Iraq since Nov. 2, when seven also were killed in four separate attacks, and it raised to at least 2,082 the number of U.S. service members who have died since the war began in 2003, according to an Associated Press count.

Jabr appeared with senior commanders to try to defuse a crisis that grew Tuesday after Prime Minister Ibrahim al-Jaafari, under pressure from the Americans, announced that 173 detainees had been found by U.S. soldiers at the Jadriyah facility. Some appeared malnourished and showed signs of torture, he said.

Most of the detainees were believed to be Sunni Arabs, prompting Sunni politicians to demand an international investigation. Sunni leaders, who have long complained of sectarian abuse by Shiite-led security forces, accused the government of trying to intimidate them from voting in the Dec. 15 parliamentary election.

Shiites and Kurds dominate the government's security services, while most of the insurgents are Sunni Arabs.

Jabr said only seven detainees showed signs of abuse "and the people behind the beatings will be punished according to the law." He also said the group included Shiites as well as Sunnis, although he gave no breakdown.

"I reject torture and I will punish those who perform torture," Jabr said. "No one was beheaded, no one was killed."

Maj. Gen. Rick Lynch, a senior U.S. military officer in Iraq, told reporters that U.S. troops, led by U.S. Brig. Gen. Karl Horst, went to the Jadriyah facility because a 15-year-old boy was believed to be held there illegally. Interior Ministry officers denied the U.S. troops entrance until Horst made a phone call to Jabr, who ordered the officers to allow the general and his men inside, Lynch said.

"When he entered the facility, Gen. Horst saw 169 individuals that had been detained. Some of those individuals looked like they had been abused, malnourished and mistreated," Lynch said. "Gen. Horst and his soldiers took control of the facility, took appropriate actions with the Iraqi leadership and the Iraqi government."

U.S. officials refused to discuss exactly how many detainees appeared to be mistreated or give any other details, citing the investigation currently under way.

The U.S. Embassy said in a statement that it was "united" with the Iraqi government in deploring the mistreatment of detainees.

"Detainee abuse is not and will not be tolerated by either the Iraqi government or the Multi-National Forces in Iraq," it said.

"We have made clear to the Iraqi government that there must not be militia or sectarian control or direction of Iraqi Security Forces, facilities or ministries," the U.S. Embassy said.

The embassy said Iraq's government said it will take "immediate action" to investigate the incident, adding that the United States would help it conduct a "fair investigation."

The spokesman for a Sunni clerical association disputed Jabr's claims, telling reporters that his group would not trust the findings of any investigation in which the Iraqi government played a role.

"We are not accusing anybody, but our people are being arrested by (Interior Ministry units) and then their bodies are found," Abdul-Salam al-Kubais of the Association of Muslim Scholars said. "If the minister is not aware of this, then he should resign."

On Wednesday, Sunni leader Adnan al-Dulaimi said he had complained to the government about abuses at three Interior Ministry compounds — a military prison in Mansour, a camp near Taji and the Interior Ministry camp at Muthanna airfield in western Baghdad.

Al-Dulaimi and several other Sunni politicians demanded an international inquiry.

Jabr said one of his Sunni critics operated a lucrative security company employing former members of Saddam Hussein's Baath Party, and "whenever there are differences between us, he exerts pressure on me through the U.S. Embassy."

He also said "those who are supporting terrorism are making the exaggerations" about torture by the Interior Ministry.

"They have described the Interior Minster's office as a place of execution," Jabr said. "Let him come to show me if there is an execution place in this shelter."

The Sunni call for an international investigation drew support from Manfred Nowak, a special U.N. investigator on torture.

"That torture is still practiced in Iraq after Saddam Hussein, that is no secret," Nowak told the AP. "It is shocking, but on the other hand, we have received allegations of these secret (detention) places in Iraq already for quite a long time."

Some ordinary Sunnis saw the hand of Shiite-dominated Iran, which offered sanctuary to many Iraqi Shiites during Saddam Hussein's Sunni-led regime.

"Some government officials want to keep the Sunnis away from the next elections by terrorizing us," Saad Farhan, a Sunni merchant in Ramadi, said, adding his brother and cousin had been held in Jadriyah. "We believe that Iran's agents are behind it because normal and genuine Iraqis never do this."

Raad al-Dulaimi, a farmer near Ramadi, said security services were dominated by "pro-Iranian elements" bent on "settling old sectarian scores with the Sunnis."

The report of the U.S. Marine killed Wednesday in Haditha, 140 miles northwest of Baghdad along the Euphrates River, meant that at least 53 U.S. service members have died in Iraq in November. That included a soldier who died Thursday in a traffic accident near Beiji, 155 miles north of Baghdad.

For the Marines, it was the worst single-day loss since they launched an offensive Nov. 5 to push al-Qaida-led insurgents from towns along the Euphrates River used by foreign fighters to slip into the country from Syria. Five of the Marines were killed as an explosion occurred as a squad entered a farm house in Obeidi, 185 miles northwest of Baghdad, according to a New York Times reporter traveling with the U.S. forces.

Insurgents then raked survivors and rescuers with small-arms and grenade fire before other Marines could recover the dead and wounded and kill the attackers, the newspaper said. Eleven Marines were wounded in the ambush, the Times reported.

The military said 16 insurgents were killed in the fighting.

U.S. officials say the offensive near the Syrian border is aimed in part at encouraging Sunni Arabs to vote in next month's parliamentary elections without fear of insurgent reprisals. The Bush administration hopes a successful election will encourage many in the Sunni community to abandon the insurgency.