Iraq announced plans Thursday to move members of an Iranian opposition group to a former desert detention camp in a sharp escalation of pressure on a faction that poses complications for both Baghdad and Washington.

The group, the People's Mujahedeen Organization of Iran, strongly denounced the plans as "unlawful and disgraceful" and said they were part of efforts to force its members to leave Iraq.

About 3,500 members of the group — which was hosted in Iraq for years by Saddam Hussein — have been under watch at a camp in northeastern Iraq since the U.S.-led invasion in 2003. But Iraqi authorities have increasingly taken a hard line toward Camp Ashraf, including a raid by security forces in July that touched off a melee in which 11 people were reportedly killed.

The group puts U.S. and Iraqi officials in a bind.

Washington lists the People's Mujahedeen as a terrorist organization and keeps its distance from Iraq's efforts to break up the group, which opposes Iran's ruling clerics. But some U.S. officials have expressed worry that Iraq's plan to forcibly move the group from its present location in Camp Ashraf could bring violence.

Iraqi leaders also would face a huge outcry from the West by deporting the exiles to their homeland, where they are considered enemies of the state. But Iraq's Shiite-led government also does not want to continue to host them and risk souring its important relations with Shiite power Iran.

The Iraqi plan, announced on a government Web site, calls for moving the exiles from Camp Ashraf to a remote desert outpost that was used as a detention facility in the 1950s. The group would first be housed in Baghdad before eventual transfer to the desert site, Neqrat al-Salman, about 200 miles (120 kilometers) west of the southern city of Basra.

The transfer could begin as early as next Tuesday, when Iraqi officials have invited media to visit Camp Ashraf.

The Iraqi statement claimed the shift was necessary because of the group's "historical relations" with factions including Saddam's regime and members of Al Qaeda. The government has accused Al Qaeda and members of Saddam's banned Baath Party of carrying out recent bombings, including Tuesday's blasts around Baghdad that killed 127 people.

A statement from the Iranian opposition group called the allegations of Al Qaida ties "ridiculous" and accused Prime Minister Nouri al-Maliki of bowing to demands from Iran to crack down on the group.

The statement also warned that Iraq's officials were bringing "another humanitarian catastrophe."

Shahriar Kia, a spokesman at Ashraf, said residents had no weapons to fight Iraqi security forces, but vowed to resist as "unarmed and defenseless" opponents.

"We will not leave our homes," he said. "We will not leave."

Last week, a vice president of the European Parliament, Alejo Vidal-Quadras, wrote a letter to al-Maliki warning "any forcible displacement" from Camp Ashraf "would no doubt lead to far greater casualties" than the July raids.

In Spain, a judge this week asked Iraq if it is investigating the July violence in the camp — a first step toward a possible probe by the judge himself.

Judge Fernando Andreu is acting under Spain's universal justice doctrine, which allows grave crimes alleged to have been committed in other countries to be prosecuted there, so long as certain conditions are met. One such caveat is that the country where a crime allegedly occurred is not holding — or already carried out — an investigation of its own.