By 9 p.m., protesters had gathered outside of Grand Central Terminal, causing authorities to limit access to the station.
According to the Instagram post, a teach-in was scheduled for 4 p.m., at Columbus Circle, followed by a 5 p.m. rally to protest Israel's war in Gaza and support Palestinians.
"Flood Manhattan For Gaza", the post said.
Video on social media showed Palestine supporters banging and kicking the doors of Grand Central Terminal in an attempt to get in after being locked out by the NYPD.
There is no word on any arrests.
The rally comes after thousands of New York City students, teachers, and staff flooded the streets of Manhattan on Thursday.
Pro-Palestinian protesters holding banners and Palestinian flags gather to stage a demonstration in streets and march through the streets in New York. (Photo by Fatih Aktas/Anadolu via Getty Images)
The Palestinian Youth Movement and other groups called for people to walk out of their workplaces, schools or other activities to join the 3 p.m. rally.
After an initial rally in Bryant Park, a large group of protesters moved to the New York Times building on Eighth Avenue, where a small group staged a sit-in at the offices of the New York Times before heading to Times Square.
Protesters demanded an immediate cease-fire in Gaza, while accusing the media of showing a bias toward Israel in its coverage of the war.
At around 5 p.m., a small group of demonstrators led by media workers calling themselves "Writers Bloc" entered the atrium of the Times building carrying a banner calling for a cease-fire.
They remained for over an hour, reading off the names of thousands of Palestinians killed in Gaza, including at least 36 journalists whose deaths have been confirmed since the war began.
They scattered editions of a mock newspaper — "The New York War Crimes" — that charged the media with "complicity in laundering genocide" and called on The Times’ editorial board to publicly back a cease-fire.
Photos showed the word "Lies" painted across the doors of the Times headquarters. It wasn’t immediately clear if anyone was arrested during the sit-in.
An email sent to New York Times staffers by the publication’s head of corporate security described the protest as "peaceful," noting that "no entrances are blocked."