Men hold up a picture of slain lawyer and prominent Libyan political activist Abdelsalam Al-Mosmary, during his funeral in Benghazi. Hundreds took to the streets overnight to denounce the killing of a prominent critic of the Brotherhood, who was shot dead on Friday after leaving a mosque. – Reuters TRIPOLI – Libya's prime minister said he would reshuffle the cabinet and reorganize the government to cope with the “urgent” situation in the country following killings in the eastern city of Benghazi that sparked violent demonstrations. Hundreds took to the streets overnight to denounce the assassination of a prominent political activist and critic of the Muslim Brotherhood, Abdelsalam Al-Mosmary, who was shot dead on Friday after leaving a mosque in Benghazi. The demonstrations turned violent, and on Saturday protesters attacked the Benghazi and Tripoli offices of the Muslim Brotherhood's political party and the headquarters of a liberal political coalition in the capital. Mosmary, one of the first activists to take to the streets in Libya's February 2011 uprising, was an outspoken opponent of the Brotherhood, whose Islamist political wing is the second biggest party in Libya's General National Congress (GNC). Two military officials were also killed in Benghazi on Friday. Libya's government is struggling to assert its authority over armed groups that helped topple veteran leader Muammar Gaddafi in 2011, part of the wave of Arab Spring uprisings that also felled autocrats in Tunisia, Egypt and Yemen. “We are about to make a cabinet reshuffle and decrease the number of ministries to ensure a better performance to face the urgent situation,” Ali Zidan told a news conference, without giving details. “What is happening is an attempt to obstruct the state's progression.” Zidan referred to the assassinations in Benghazi but made no reference to the storming of the parties' offices. Libya's border with Egypt was closed to prevent Mosmary's killers from fleeing, he said, with only cargo trucks allowed to pass. Earlier on Saturday, protesters in Benghazi invaded and set fire to a building housing the Muslim Brotherhood's political wing, the Justice and Construction Party (JCP), witnesses said. “They shouted ‘Gather your belongings. Benghazi wants you out',” Benghazi resident Rami Al-Shahibi said. Hundreds gathered outside Benghazi's Tibesti hotel, one of the main squares in the city for demonstrations, for funeral prayers for Mosmary before heading to a cemetery. They continued to shout anti-Brotherhood slogans. In Tripoli, a crowd stormed JCP headquarters before heading on to ransack the headquarters of the liberal National Forces Alliance (NFA), the country's biggest political party founded by wartime rebel prime minister Mahmoud Jibril. There has been rising opposition in Libya to the influence of the Muslim Brotherhood, which has links to several government ministers. The movement has struggled to convince Libyans wary of foreign interference that it has no financial or administrative links to its namesake in Egypt, whose Islamist president Mohamed Morsi was overthrown by the army on July 3. Tensions are also high between secularists and the ruling Islamists in Tunisia, where the funeral of an assassinated secular politician took place on Saturday. Many of the protesters accused the Brotherhood of being behind the killings in Benghazi, cradle of the 2011 revolution and now a hotspot for violence — a charge rejected by Abdulrahman Al-Dibani, a JCP member in congress. — Reuters