Two days after they were arrested at a demonstration marking the fifth anniversary of an Arab Spring-inspired uprising in Bahrain, four Americans have now been released. They are accused of illegal assembly and intent to commit a crime.

Bahraini officials say the four entered the country illegally — evidently by identifying themselves as tourists instead of journalists — and then took part "in an unlawful gathering."

One of the Americans who was detained is Anna Therese Day, according to CNN, which says Day has done freelance work for the network and other news outlets.

Providing new details, Bahrain's Police Media Center says the arrests began when police detained a masked man who was near "rioting and vandalism" in an area where security forces were also being attacked.

That led police to question the three other Americans, who were nearby — and police determined that they had been "carrying out media activities without receiving the permit from the competent authorities," as Gulf News reports.

A prosecutor in Bahrain issued a statement Tuesday saying the four "were released on Tuesday afternoon," The Associated Press reports, adding, "It wasn't immediately clear if they could leave the island nation off the coast of Saudi Arabia."

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