MIAMI, Nov 26 (Reuters) - Rights group Amnesty International on Wednesday called for a full investigation into allegations police in Miami used excessive force during protests against a regional free trade meeting last week.

Amnesty urged a fully independent investigation to look, among other things, into reports that some of the 250 or so people detained were abused and ill-treated in jail.

"The level of force used by police does not appear to have been at all justified," the group said in a statement.

The center of the subtropical U.S. city was closed down by squads of riot police during the Nov. 17-21 Free Trade Area of the Americas meeting, at which hemispheric trade ministers negotiated but failed to set up what would be the world's largest free trade zone.

Armored vehicles patrolled the streets, police helicopters hovered overhead and, during street clashes on Nov. 20, police fired volleys of rubber bullets and pepper spray at protesters in the city center.

A few dozen of the estimated 15,000 demonstrators threw rocks or a white paint-like liquid at police.

Activists, who say the FTAA and other trade accords will eradicate jobs, destroy the environment and erode human rights, are threatening to sue over civil rights abuses and are calling for the head of Miami police chief John Timoney.

They say at least 10 detainees were beaten in jail and they had received four reports of sexual assault while in custody.

"Timoney and (Miami Mayor Manny) Diaz suspended the constitution to achieve their version of 'homeland defense,'" said Brenna Bell, a lawyer with a group called Miami Activist Defense.

She was referring to a comment by Diaz that the massive Miami police operation to avoid a repeat of the riots that marred a 1999 World Trade Organization meeting was a model for post-Sept. 11, 2001, U.S. defense against domestic attack.

John Sweeney, president of the U.S. labor federation AFL-CIO, which represents around 13 million trade union members, said on Wednesday the organization was deeply disturbed by the crushing of dissent in Miami.

"It is clear that the protesters' basic right to have their voices heard was severely restricted, and that all Americans' civil liberties took a one-two punch in Miami," he said.