Saturday's clashes in Libya came after the assassination of a prominent critic of the Brotherhood. Hundreds took to the streets overnight to protest the Friday killing of prominent political activist Abdul-Salam Al-Musmari, who was killed as he left a mosque.

Musmari was an outspoken opponent of the Muslim Brotherhood, whose political wing is currently the second biggest party in Libya's General National Congress.

Jailbreak amid protests

"We don't want the Brotherhood, we want the army and the police," some protesters chanted, echoing a slogan used in Egypt.

On Saturday, protesters in Libyan cities stormed Islamist-affiliated party offices. In Benghazi, they invaded and set fire to a building the Muslim Brotherhood's political wing occupies.

During the chaos, a jailbreak was launched at Benghazi's Koyfiya prison, government security official Mohammed Hejazi said. It was unclear whether the jailbreak was part of the protests or if the inmates received help from outside.

A security official from the prison said most of the inmates being held were convicted on serious charges.

In Tripoli, meanwhile, a crowd stormed the Brotherhood political wing office before heading over to the headquarters of the liberal National Forces Alliance and ransacking it. Protesters in Tripoli also set fire to tires in the street and demanded the dissolution of Islamist parties.

Protesters seemed to be inspired by events in neighboring Egypt, where millions took to the streets Friday to answer a call from the army chief, who said he wanted a mandate to stop "potential terrorism" by supporters of the country's ousted president and Brotherhood-aligned Mohammed Morsi. 

'Fragile transition at stake'

Human Rights Watch urged the Libyan government on Saturday to "conduct a prompt and thorough investigation" into al-Musmari's death, urging the nation to continue building a democracy.

"Libya's fragile transition is at stake if political killings go unpunished," said Nadim Houry, deputy Middle East and North Africa director at Human Rights Watch. "This makes investigating al-Musmari's murder all the more urgent."

tm/slk (AP, AFP, Reuters)