Bahrain's ministry of interior said yesterday it would take legal action against the largest Shia opposition bloc, Al Wefaq, for holding an unlicensed rally in central Manama on Friday.
The case "will be referred to the public prosecution", a ministry statement announced.
The ministry blamed Al Wefaq for encouraging the protest, which led to "blocking of roads, vandalism and the spreading of fear among the business owners in the area", the statement said. Six protesters were arrested during the demonstrations.
"The ministry affirms its support for free speech but reminds all citizens that freedom of expression does not include vandalism," the statement said. Al Wefaq and several other opposition groups had called the protests in response to verdicts against 13 opposition leader earlier last week.
The government alleged that they were attempting to overthrow the government during Arab Spring protests that erupted last year, but the defendants argued that they were simply asking for democratic reforms.
Al Wefaq had applied for a licence to protest one day in advance, according to the ministry of interior statement, but their request had been denied because the protest route "negatively affected businesses in the major business corridor". Despite lacking official permission to protest, dozens of activists gathered in Manama on Friday afternoon, in what witnesses said was the largest demonstration since the government lifted a blanket ban on such gatherings earlier this summer.
Traffic was paralysed going in and out of the central business district as police set up checkpoints.
Al Wefaq rejected the accusations the protest hurt commercial activity, saying that they had gathered for a peaceful protest that was intended to last just one hour on Friday evening, at a time when most businesses were not operating.
"We practiced our right and the people practiced their right," said Khalil Marzouk, a former Al Wefaq MP, by phone from Bahrain.
"The ministry of interior is saying that we have blocked the roads, but it is the opposite: Beginning at 2pm, they blocked the entrances to Manama."
Activists who participated in the protest said that the security presence was heavier than usual. And Al Wefaq blamed police for beating and verbally abusing protesters.
According to the Bahrain state news agency's Arabic website, the country's prime minister, Khalifa bin Salman Al Khalifa, said he would not allow protests that could jeopardise national economic activity.
He promised to take action against those who sought to "harm national interests".