NEW YORK — US federal prosecutors said Thursday they were moving to seize four mosques and a 36-story New York skyscraper from a non-profit Muslim group suspected of having ties to the Iranian government.

The Alavi Foundation has been providing "numerous services" and illegally funneling funds to the Iranian government through money laundering, according to the office of US Attorney for the Southern District of New York Preet Bharara.

Bharara filed a forfeiture action with a New York federal court to seize bank accounts owned by the group and a suspected front company, as well as the office tower and Islamic centers in the states of Maryland, Virginia, Texas and California.

"As today's complaint alleges in great detail, the Alavi Foundation has effectively been a front for the government of Iran," Bharara said in a statement.

"For two decades, the Alavi Foundation's affairs have been directed by various Iranian officials, including Iranian ambassadors to the United Nations, in violation of a series of American laws."

Washington has long accused Tehran of funding terror groups and of seeking to produce a nuclear bomb under cover of its suspect civilian nuclear program.

President Barack Obama renewed long-standing US economic sanctions against Iran for another year on Thursday, telling Congress that "our relations with Iran have not yet returned to normal."

The move to seize the Shiite Muslim places of worship, a very rare step for US law enforcement due to freedom of religion rights enshrined in the Constitution, comes as US Muslims fear a backlash following last week's shootings at Fort Hood, Texas, allegedly by a Muslim US Army psychiatrist.

The seized Islamic centers house mosques and schools.

Prosecutors said the foundation sent the funds, including rental income from the Fifth Avenue skyscraper, to Iran's state-owned Bank Melli through Assa Corporation and its parent organization, Assa Company Limited.

The US Treasury has already designated the two groups as being fronts for Bank Melli, which it says supports Iran's nuclear program and provides banking services to the country's elite Islamic Revolutionary Guards Corps and its Quds Force branch.

In 2007, the Treasury placed Bank Melli on its list of companies whose assets must be frozen.

In a December notice, it had mentioned the office tower located at 650 Fifth Avenue, saying Bank Melli created Assa Corporation to hold its interest in the building and citing the Alavi Foundation as a co-owner.

Bharara noted that the group's former president is still under investigation for alleged obstruction of justice, while criminal and civil investigations are ongoing.

The Alavi Foundation was founded as a successor to the Pahlavi Foundation, a non-profit organization the shah had used to pursue Iran's charitable interests in the United States.

But after the fall of the shah during the 1979 Islamic revolution, the revolutionary leadership changed the group's agenda, placing it under the purview of the Bonyad Mostazafan, which reported directly to Iran's supreme leader, the grand ayatollah.