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The crowd played Palestinian music and repeated chants such as “ceasefire now” at the sit-in, which was organised by direct action group Sisters Uncut.
Videos posted online by the protest group showed a large group of demonstrators inside the station during rush hour, chanting and waving pro-Palestinian flags and banners.
Members from other activist groups, including the Palestinian Youth Movement and International Jewish Anti-Zionist Network, also spoke at the demonstration.
British Transport Police said it attended Liverpool Street station shortly after 5pm following reports of a protest on the concourse.
"Officers worked to safely disperse the crowd and ensure passengers could access the station," a statement from BTP said.
Sisters Uncut describes itself as a feminist group against domestic violence, and held a similar pro-Palestinian demonstration with more than 200 people at London Waterloo station on Saturday.
Earlier on Tuesday, Labour leader Keir Starmer resisted pressure from within his own party to call for a ceasefire in the conflict.
Mr Starmer instead urged both parties to agree to a humanitarian pause to allow aid in and people out of the war zone.