MANAMA (Reuters) - Bahraini authorities are taking legal action against the opposition Al Wefaq group for organizing a banned anti-government march in which six protesters were arrested, the Interior Ministry said on Saturday.
It was not immediately clear what the action might entail, but the government has threatened to ban the group in the past and its statement comes despite calls from Washington for Bahraini leaders to pursue a meaningful dialogue with the opposition.
Bahrain, where the U.S. Fifth Fleet is based, has been in political turmoil since a protest movement dominated by majority Shi'ite Muslims erupted in February last year.
Opposition parties led by Al Wefaq are demanding full powers for the elected parliament to legislate and form governments. Many Shi'ites complain of being politically and economically marginalized, which the government denies.
Police used teargas and stun grenades to break up Friday's march, which dozens of protesters took part in.
"The Interior Ministry holds Al Wefaq responsible for violating the law and encouraging their supporters to participate in a non-sanctioned event," said a statement from the ministry distributed by the government's public relations office.
The statement said Al Wefaq had been told a day earlier that its protest had not been authorized and that the demonstrators engaged in "the blocking of roads, vandalism and spreading fear and concerns among the business owners in the area".
"The ministry affirms its support for free speech but reminds all citizens that freedom of expression does not include vandalism, spreading fear amongst the community and attempting to create chaos?. The ministry has taken legal action to file a case against Al Wefaq," it said.
It added that the ministry had also filed cases with the public prosecutor against the six arrested protesters.
"Wefaq has been threatened in the past, but the level and the wording, all of these show it is possibly more serious than at any other time," Jasim Husain, one of the group's leaders, said.
"But they are not threatening yet a ban. The wording is legal action."
Armored vehicles and riot police had closed off some of the main roads leading into the city, but dozens of protesters attended the march, which had been tweeted as "freedom for prisoners of conscience".
Last week, a march attended by tens of thousands of demonstrators that had also been organized by Al Wefaq together with other opposition groups and which the authorities had approved passed off without incident.
On Tuesday jail sentences of between five and 25 years against leaders of last year's uprising were upheld by a civilian court, prompting condemnation by Al Wefaq.
The United States in June said it was "deeply disappointed" that a Bahraini court had upheld verdicts against medics accused of participating in last year's uprising, while President Barack Obama last year called on the government to talk to Al Wefaq.
(Writing by Angus McDowall in Riyadh; Editing by Alison Williams)