Bahrain charges US journalist Anna Therese Day and colleagues held on Arab Spring anniversary

Bahraini prosecutors charged a group of US journalists arrested on the anniversary of the Arab Spring uprising with illegally assembling with the intent to commit a crime. The four reporters were freed from custody after international pressure for their release but it was not immediately clear if they were allowed to leave the tiny island kingdom.

Authorities in the small nation off Saudi Arabia initially detained the journalists on 14 February on accusations of participating in a riot against police falsely stating they were tourists. The Ministry of Interior did not release the identities of the four but said the group included a woman who was named by her family as award-winning journalist Anna Therese Day.

Lawyer Mohammed al-Jishi told AP his clients were quizzed for about an hour on the morning of 16 February. In the afternoon they were let go, prosecutors said in a statement.

Day and her camera crew were arrested in Sitra, a majority Shia town where protesters marking the anniversary of the 2011 mass demonstration violently clashed with security forces on 14 February. It was not clear if the reporters were in the country on a specific assignment. Photos circulating on social media appeared to show Day speaking to a protester.

'Participating in attacks'

Police said they first arrested a photographer with the group who was allegedly "wearing a mask and participating in attacks on police alongside other rioters in Sitra". The other three people were later held at a checkpoint and accused of falsely entering the country on a tourist visa while doing journalism work.

"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 Ministry of Interior said in a statement.

Press freedom groups, including Reporters Without Borders, the Committee to Protect Journalists (CPJ) and the Frontline Freelance Registed called for their immediate release. "It is sad that the fifth anniversary of the 2011 protests has been 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 CPJ's Middle East and North Africa program coordinator Sherif Mansour.

CPJ said at least six more journalists are currently in custody in Bahrain because of their work.

A spokesperson for Day's family said they were concerned about her well-being and that of her colleagues. "Anna and her crew are committed journalists who only want to ensure they could undertake their profession ethically and thoroughly. The allegation that they were in any way involved in illegal behaviour or anything other than journalistic activities is impossible," the spokesperson said.

Alexandra El Khazen, the head of Reporters Without Borders Middle East Bureau, said it has become increasingly more difficult for foreign reporters to obtain a working visa in Bahrain after the 2011 uprising.

Protests that began in the February five years ago embodied the vexation of the majority Shia population at the rule of the Sunni royal family. Demonstrators lamenting sectarian discrimination and demanding democratic reform were driven out by force with the help of Saudi Arabia.

The brutal crackdown drew widespread criticism from rights groups and King Hamad al-Khalifa gave in to international pressure with a pledge to implement reform recommendations from an independent commission of inquiry but reforms have since progressed slowly and discontent continues to simmer within the Shia population.

The US embassy said it was aware of the arrests and Bahrain ambassador William V Roebuck reportedly met with Bahraini Crown Prince Salman bin Hamad Al Khalifa on 15 February. Bahrain hosts the US Navy's 5th Fleet.

Day from Boise, Idaho, has contributed to the New York Times, CNN, The Huffington Post and The Daily Beast.