TRIPOLI, Libya (AP) -- Scores of Libyan militiamen descended on rally in the nation's capital, Tripoli, kicking and beating protesters who had taken to the streets Friday as part of a call for mass demonstrations against the country's unruly militias.
Rallies also took place in two other Libyan cities, Benghazi and Tobruk, with hundreds of activists denouncing the armed thugs and decrying what they describe as political maneuverings by the nation's Muslim Brotherhood.
For nearly two weeks, Libya has been gripped by fear of new armed conflict after militias stormed and surrounded government buildings in Tripoli, blocking access to ministries in an attempt to push parliament to pass a contentious law that would prevent members of Moammar Gadhafi's regime from serving in senior government posts.
The turmoil appears to have sent jitters beyond Libya's borders, with the U.S. and Britain expressing concern over the prospects of continuous unrest in the North African country.
Libyan lawmakers approved the bill during the weekend, with guns still drawn on the streets, and the militias seemed to be gradually lifting their siege in the capital. But witnesses said they remained hunkered down inside the Foreign and Justice Ministry, paralyzing the institutions and preventing employees from coming to work.
Their show of force has left many Libyans fearful over the country's rocky transition to democracy.
In Tripoli, the day started peacefully, with activists marching in the streets with placards reading: "Law under the guns; constitution under fire" -- a reference both to the recent siege and Libya's new constitution, which is to be drafted next year.
Others waved signs reading, "No to Mooq Mooq" -- a word used to mock militias.
As the rally marched by the two ministry buildings, the militiamen descended and started hitting the protesters.
"They beat us up, women fled and a number of young men were seized and taken away," said Abdel-Moaz Banoun, one of the protesters. "We have no clue who took them or where they are now."
Banoun told AP a Foreign Ministry official was among those seized.
Justice Minister Salah al-Marghani, who had joined the protest, told Libya's Al-Ahrar TV network that the militiamen threatened him. "They told me I will be responsible for the bloodshed," he said.
The protesters then dispersed but said they will march again today.
The other two rallies Friday in Libya passed without violence. In the eastern city of Benghazi -- the birthplace of the 2011 uprising that evolved into an eight-month-long civil war and ended with the ouster and killing of Gadhafi -- hundreds protested against the Muslim Brotherhood.
The Islamist group is charged with engineering the new law, set to take effect in early June. The legislation could remove a whole class of post-Gadhafi officials -- including the head of the current parliament, Mohammed al-Megarif.
While the law might also affect Brotherhood members and other ultraconservative Islamists, it would get rid of Brotherhood's top foe, Mahmoud Jibril, a war-time prime minister and who enjoys wide popularity in the country.
Jibril was a top aide to Seif-Islam, one of Gadhafi's sons and heir apparent, before he defected to the rebels. His coalition, The National Forces Alliance, won the biggest number of parliament seats allocated for political groupings in the July parliament elections.
"No to Brotherhoodization of the state," read a banner held by a Benghazi protester. The term is used to express fear of the Islamist group installing its loyalists in government posts. Other protesters hanged an effigy of the ruler of Qatar, the country Libyans see as a key Brotherhood backer.
"From the dictatorship of Gadhafi to the dictatorship of the Muslim Brotherhood," another sign read. The Brotherhood came second in the July elections, after Jibril's alliance, but rivals accuse the group of wielding significant power and getting funding from abroad.
A similar protest took place in the eastern city of Tobruk, where advocates for a semi-autonomous eastern region are active.
After the fall of Gadhafi, Libya was left without a strong police force or unified military, and the new authorities had no option but to depend on former rebels and mushrooming number of militias to maintain law and order. However, the militias soon became a source of trouble and at the same time, the security deteriorated.
In Benghazi, series of assassinations and bombings of police stations have prompted diplomatic missions to leave over the past year. On Sept. 11, Islamic militants attacked the U.S mission there, killing U.S. Ambassador Chris Stevens and three other Americans.
On Friday, two bombs exploded outside police stations in different districts of Benghazi. No injuries were reported, but the state news agency said buildings and vehicles were damaged.
Last month, a car bomb hit the French Embassy in Tripoli, wounding three people and partially setting the building on fire. It was the worst attack on a diplomatic mission in Libya since Steven's slaying.
No group has claimed responsibility for any of the attacks.
On Friday, an American military official said U.S. forces in Europe are on a heightened state of alert in response to a deteriorating security situation in the Libyan capital. The official, who was not authorized to discuss the matter publicly, spoke on condition of anonymity.
The alert order came a day after the State Department said it was advising U.S. citizens against all but essential travel to Tripoli and all travel to Benghazi and other locations in Libya. It cited "ongoing instability and violence" and said the State Department's ability to provide consular services to U.S. citizens there was "extremely limited."
Meanwhile, Britain's Foreign Office says it temporarily withdrew some staff from its embassy in Tripoli in light of the recent political unrest.
Associated Press writer Robert Burns in Washington contributed to this report. Michael reported from Cairo.