Newsweek magazine said it may have been mistaken in an article that alleged U.S. interrogators flushed the Qur'an down the toilet.

Protests erupted Tuesday after the magazine reported in a recent edition that investigators at the U.S. Navy base at Guantanamo Bay, Cuba, placed the Muslim holy book in washrooms to prompt detainees to talk.

The May 9 report quoted unnamed sources as saying that the interrogators had "in at least one case, flushed a holy book down the toilet."

Newsweek Editor Mark Whitaker apologized to victims of the violence triggered by the allegations of desecration.

"We regret that we got any part of our story wrong, and extend our sympathies to victims of the violence and to the U.S. soldiers caught in its midst," Whitaker wrote in the magazine's latest issue, set to appear on U.S. newsstands Monday, Reuters reported Sunday.

The article sparked demonstrations across the Muslim world.

In Afghanistan, 15 were killed and more than 100 wounded in anti-U.S. protests that erupted across the country.

The Arab League, based in Cairo, Egypt, also issued a statement saying Washington should apologize to Muslims if the allegations were correct.

Meanwhile, U.S. ally and Pakistan President Gen. Pervez Musharraf called for an investigation on the report.

In Yemen on Saturday, thousands of university students hit the streets in a demonstration, chanting "Death to America!"

Newsweek reported that a Pentagon spokesman told the publication late last week that the claims were wrong and that the military found no evidence to support allegations of desecration.

Many of the 520 inmates at Guantanamo Bay are said to be Muslims arrested during the American-led war on terror.

With files from The Associated Press