MANAMA, Bahrain (AP) -- Bahraini prosecutors on Tuesday charged four U.S. journalists detained while covering the anniversary of the country's 2011 unrest with illegally assembling with the intent to commit a crime.
The four were released after they were charged, though it wasn't immediately clear from the prosecutors' statement whether they could leave the country off the coast of Saudi Arabia.
Bahrain police said they detained the four Americans on Sunday for providing "false information that they were tourists" and also alleged that one took part in an attack on Bahraini officers.
In a statement, Manama's chief prosecutor Nawaf al-Awadi said the journalists' possession of cameras and computers sparked their investigation. It said the journalists were freed "pending the completion of the investigation."
Only one of the four journalists has been identified so far, freelancer Anna Therese Day of Boise, Idaho.
A friend of Day's, Jesse Ayala, has said the journalists were simply doing their job and denied they took part in any "illegal behavior." Day had previously contributed to The Huffington Post and The Daily Beast. Police said one of the journalists was a woman and three were men.
On Sunday, police arrested a photographer working with the group, two witnesses said. Later that night, police surrounded the area with checkpoints and arrested the other three, they said. The witnesses spoke to The Associated Press on condition of anonymity for fear of being arrested.
An Interior Ministry statement alleged one of the four journalists "was wearing a mask and participating in attacks on police alongside other rioters in Sitra." The statement also said the journalists entered the country between Thursday and Friday on tourist visas.
"At least some of the arrestees were in the country as members of the international media but had not registered with the concerned authority and were involved in illegal activities," the statement said, without elaborating on what those activities were.
Bahrain requires international journalists to obtain special media visas before entering to work. The island kingdom allows citizens of many countries, including the United States, to get a tourist visa on arrival. Obtaining a media visa takes several days, and activists say Bahrain has denied media visas for some journalists since the 2011 protests.
A statement on the state-run Bahrain News Agency said the journalists had "been afforded full legal rights in line with the kingdom's procedures and constitution while investigations continue."
Bahraini officials did not respond to questions from the AP about the arrests.
U.S. Ambassador William V. Roebuck also met with Bahraini Crown Prince Salman bin Hamad Al Khalifa on Monday, according to a late statement on the Bahrain News Agency.
The 2011 protests in Bahrain, which is home to the U.S. Navy's 5th Fleet, were the largest of the Arab Spring wave of demonstrations to rock the Gulf Arab states. They were driven by the country's Shiite majority, which demanded greater political rights from the Sunni-led monarchy.
The protests were quashed after Saudi Arabia and the United Arab Emirates sent in reinforcements. Bahrain blamed regional Shiite power Iran for stirring up the demonstrations, though a government-sponsored investigation into the unrest said there wasn't a "discernable link" between the protests and the Islamic Republic based on the information the government gave them.
Bahrain's government committed to a number of reforms in the wake of the 2011 demonstrations, but low-level unrest continues, particularly in Shiite communities. Small groups of activists frequently clash with riot police and bombs occasionally target security forces. Hundreds of Bahraini youths protested Sunday on the fifth anniversary of the uprising.
The New York-based Committee to Protect Journalists called for the immediate release of the American journalists, saying at least six other reporters are being held by the kingdom over their work.
"It is sad that the fifth anniversary of the protests is marked by the arrest of yet more journalists in Bahrain, which has since become one of the worst jailers of journalists in the Arab world," said Sherif Mansour, the committee's Middle East and North Africa program coordinator.