The United States on Wednesday voiced concern at Bahrain's ban on all protests and public gatherings, urging the Gulf state to find a way to allow peaceful demonstrations to resume.

"The United States is deeply concerned by the Bahraini government's decision to ban all public gatherings. Freedoms of assembly, association and expression are universal human rights," acting State Department spokesman Mark Toner said.

"We urge the government of Bahrain to work with responsible protest leaders to find a way for peaceful and orderly demonstrations to take place."

Curbing the right to assembly was contrary to "Bahrain's professed commitment to reform and will not help advance national reconciliation nor build trust among all parties," he told journalists.

Bahrain on Tuesday banned all protests and gatherings to ensure "security is maintained," after a spate of clashes between Shiite-led demonstrators and security forces in the Sunni-ruled country.

The Gulf state has been shaken by unrest since its forces in March last year crushed a month of popular protests led by members of its Shiite Muslim majority demanding greater rights and an end to what they said was discrimination against them by the Sunni royal family.

The crackdown, which drew strong criticism from international rights groups, was followed by a three-month state of emergency declared by King Hamad, during which protests were also banned.

Toner added Washington was also urging "the opposition to refrain from provocations and violence" adding recent attacks on security forces were "a deeply troubling development."

"Violence undermines efforts to reduce tensions, rebuild trust, and pursue meaningful reconciliation in Bahrain," he said.

"We urge the government of Bahrain to take steps to build confidence across Bahraini society and to begin a meaningful... dialogue with the political opposition."