Dozens of anarchists stormed the offices of Greece's ruling party Sunday to demonstrate in solidarity with prisoners currently staging a hunger strike against poor conditions in the country's maximum-security prisons.

Around 50 protesters rushed into the radical left-wing SYRIZA party headquarters in Athens' Koumoundourou Square, temporarily occupying several floors.

In a video posted to YouTube Sunday, the group of activists are filmed bursting into the office and rushing up the stairs before hanging a large banner from the side of the building and throwing leaflets from a balcony onto the street below.

The anarchists' list of demands included the abolition of a number of anti-terrorist laws and controversial "C-type" cells, which house convicted terrorists, many of whom are militant anarchists, and other "dangerous" prisoners deemed ineligible for parole or furloughs. Members of groups such as the neo-Nazi Golden Dawn party are also held in these types of cells.

Activists and prisoners have long called for the elimination of C-type cells, where inmates' contact with lawyers and family is severely restricted.

Last summer, 4,500 prisoners went on hunger strike for 10 days across the country to protest legislation approving construction of the self-contained high-security cells, which have been described by some as the "Greek Guantanamo Bay," or "a prison within a prison."

Over the weekend, the anarchists also called for the release of Savvas Xiros, who was convicted for his involvement in the extreme left-wing urban guerrilla group Revolution Organization 17 November, known as "RO 17N." The group has carried out numerous murders, kidnappings, and attacks on commercial and government offices in its history and Xiros, whose health is now reportedly failing, was sentenced to life in prison for being one of the group's bomb makers. The US State department classified the group as a terrorist organization in 2011.

Sunday's occupation, which lasted several hours, forced staff to leave the office temporarily, AFP reported. The Syriza party reportedly did not call police, and it is unclear whether protesters left of their own accord or were forcibly removed.

"I was inside my office giving my first official interview to a radio station," the party's spokeswoman Rania Svigou told AFP. "I had locked the door so I wouldn't be disturbed. Then I heard banging and shouting."

The protests follow a string of demonstrations against the new government's handling of the country's debt crisis, including Syriza's backtracking on promises to wipe out austerity measures and loan agreements that have crippled the nation's economy and jobs prospects.