London ? The United States and governments around the world have used the post-Sept. 11 war on terrorism to erode human rights and stifle political dissent, Amnesty International said Tuesday.

In its annual state-of-the-world report, the organization said emergency anti-terrorist legislation and changes in trial and detention procedures had contributed to an atmosphere of repression and undermined universal principles of human rights.

“What happened on Sept. 11 was a crime against humanity, a gross human rights violation of thousands of people,” said Amnesty’s secretary-general, Irene Khan.

However, she said, “in the days, weeks and months that followed, governments around the world eroded human rights in the name of security and anti-terrorism.”

Among the worrying developments, Amnesty said, were a U.S. proposal to try some terrorist suspects before military tribunals and new laws in several nations including the United States, Britain and Canada making it easier to deport or detain foreign suspects.

The London-based rights group said countries from India and Pakistan to Malaysia and Singapore had introduced repressive security legislation in the aftermath of Sept. 11.

“Human rights were traded away in almost all parts of the world,” Khan said. “Democratic states jumped on the bandwagon almost as rapidly as authoritarian regimes.”

Khan said the United States was setting a poor example by refusing to classify Taliban and al-Qaida suspects held at the U.S. Navy’s Guantanamo Bay base in Cuba as prisoners of war, which would grant them rights under the Geneva Conventions.

Also after Sept. 11, U.S. authorities gained new powers of search, detention and surveillance. More than 1,100 people, mostly Arab or Muslim men, have been detained as part of an effort to find links to terrorists. Some have been held in solitary confinement.

Britain also has detained a small number of people under laws that allow some suspects to be held indefinitely without charge or trial.