Footage showed dozens of activists shouting “ceasefire now” as they staged the sit-in protest at King's Cross station.
British Transport Police said that two people had been detained for refusing to comply with public order legislation.
One video posted on X, formerly known as Twitter, appears to show a man draped in a Palestinian flag shouting “free, free Palestine” while being carried away from the station by three officers.
Others appear to show the slogan “from the river to the sea” being shouted, with demonstrators replying “Palestine will be free”.
In videos, protesters can be seen sitting on the station concourse chanting “ceasefire now”, “free, free Palestine” and “in our thousands, in our millions, we are all Palestinians”.
A banner accusing Israel of genocide can also be seen in some clips.
The UK's Transport Secretary Mark Harper said he had given an order to allow police to stop the demonstration on Friday evening under Section 14a of the Public Order Act 1986.
The Transport Secretary said that the right to peaceful protest “cannot be at the expense of other people’s right not to be seriously disrupted or intimidated”.
“This means protest activity at the station is classified as unlawful and anyone taking part will be subject to arrest,” he added.
“Officers must have the powers they need for our stations to remain safe places for people to go about their journeys, protecting public safety and preventing disorder.”
British Transport Police confirmed the small demonstration had since moved to a nearby square.
The demonstration inside the station had ended, and trains and the station were both accessible to the public, it added.