A trail of social media posts from anti-ICE lefties fueled the chaotic protest that quickly erupted outside a Brooklyn hospital over the weekend.

The Saturday night demonstration over the detention of Nigerian national Chidozie Wilson Okeke led to nine arrests and lingering accusations from left-wing local pols and activists that the NYPD was illegally coordinating with ICE – which Mayor Zohran Mamdani vehemently denied.

A local immigration watchdog group had tailed ICE agents bringing Okeke in custody to Wyckoff Heights hospital in Bushwick, Councilwoman Sandy Nurse told the New York Times.

It came after disturbing video circulated online showing Okeke’s broad daylight arrest Saturday by ICE agents.

He could be seen screaming hysterically as ICE agents surrounded him inside a car and one seemed to fire a Taser, according to the bystander video obtained by The City.

By nightfall, a group of masked protesters showed up outside the hospital and then began to take pictures of the ICE agents, video posted on Instagram shows.

“It’s an ICE vehicle,” one young man can be heard repeatedly yelling on the video, referring to a black minivan.

Another youngster in a maroon hooded sweatshirt squares off against the minivan’s driver, who at one point appears to threaten to pepper spray him.

Whether the agitators were part of the same group as the watchdogs that Nurse mentioned was unclear.

But the masked protesters’ photos of two alleged federal immigration enforcement vehicles outside the hospital spread on social media and quickly reached ICE watchdog accounts on Instagram.

Protesters were already on scene by the time those photos were posted, according to police.