Interior ministry order is latest effort to counter anti-government uprising in which 50 people have died since early last year

This article is more than 7 years old

This article is more than 7 years old

Bahrain banned all protest gatherings on Tuesday and threatened legal action against groups said to be backing escalating demonstrations and clashes.

The interior ministry order is the most sweeping attempt to quash the anti-government uprising in the Sunni-ruled kingdom since martial law was imposed during the early months of unrest last year.

It sharply increases pressure on political groups from Bahrain's Shia majority, which has led the protests in support of a greater political voice.

A crackdown on opposition groups could raise complications for Washington and other western allies that have stood by Bahrain's monarchy during more than 20 months of unrest. The US has important military ties with Bahrain, which hosts the US navy's 5th Fleet, but it also has called for increased dialogue to ease the tensions.

Shias make up around 70% of Bahrain's 525,000 citizens, and claim they face systematic discrimination such as being denied top political and security posts. The Sunni monarchy has made a series of concessions – including giving more powers to the elected parliament – but opposition groups say the reforms do little to loosen the ruling family's grip on power.

More than 50 people have been killed in Bahrain's unrest since February 2011. Among them were two policemen who died this month from injuries suffered in attacks in which firebombs and explosives were used.

An interior ministry statement said Bahraini society was fed up with near nonstop demonstrations and clashes and that "there was a need to put an end to them". Bahrain's government has permitted limited protests and marches, but much of the violence occurs away from the authorised gatherings.

It added that any "illegal rally or gathering would be tackled through legal actions against those calling for and participating in it".

The warning appeared aimed particularly at the largest Shia political bloc, al-Wefaq, which has organised many opposition marches. Another rally is planned for Friday.

An al-Wefaq official, Hadi al-Musawi, struck a defiant tone, saying the interior ministry order was against international human rights.

Other Gulf states have placed limits on political expression amid worries that movements inspired by last year's Arab spring could threaten their ruling systems. Last week, Kuwait banned all public gatherings of more than 20 people following opposition protests ahead of parliamentary elections on 1 December.