The detention of a popular immigration advocate triggered a large protest in Lower Manhattan where 18 people were arrested, including two city council members.

Ravi Ragbir, 53, is Executive Director of the New Sanctuary Coalition, a network of faith and community groups that advocates for immigrants. But after a 2001 non-violent felony conviction, the government issued a deportation order which he's been fighting ever since.

His lawyer, Alina Das, said Ragbir and his wife were hoping Thursday's appointment at the Federal Building would be a routine check-in.

"Yet as soon as we walked into the check in, we were told that they had made a decision," she said.

Das said her client fainted when he heard the news. "They called in a nurse who saw that his blood pressure was incredibly low," she said. "It slowly was coming up and over time, they said they were going to take him for medical clearance."

She said he was handcuffed and taken away in an ambulance to be processed and brought to a detention center.

NYPD arresting demonstrators blocking street after immigration activist Ravi Ragbir detained by @ICEgov. Councilman Williams w/them @WNYC pic.twitter.com/BoPXwh3mBX

— Beth Fertig (@bethfertig) January 11, 2018

Hundreds of activists were already gathered outside the Federal Building to support Ragbir, having participated in a silent march that morning. That's when things got rowdy.

Chanting "Ravi, Ravi," and "This is a sanctuary city," demonstrators followed his ambulance and some tried to block it while it was heading south on Broadway. Police pulled the protesters away and one was even hit by the ambulance. By the time the vehicle was passing City Hall, several people sat in the road and were arrested. 

They included City Councilmen Jumaane Williams and Ydanis Rodriguez. One demonstrator, Jaime Bauer, insisted she wasn't blocking the ambulance but was on the side. City Councilman Corey Johnson came outside to monitor the situation.

"There was no violence, I didn't see violence on behalf of the protesters," he stated.

Sarah Sklaw, 26, a member of the New Sanctuary Coalition, said the protest was necessary to support immigrants. "We'll put our bodies as citizens on the line," she said.

But Immigration and Customs Enforcement defended Ragbir's detention.

"Over the last 12 years, Mr. Ragbir’s immigration case has undergone extensive judicial review at multiple levels of the nation’s judicial system, including both immigration courts and federal appeals courts," spokeswoman Rachael Yong Yow said in a statement. "In each review, the courts have uniformly held that Mr. Ragbir does not have a legal basis to remain in the U.S. In an exercise of discretion, the agency had previously allowed him to remain free from custody with periodic check-ins, while his case was under court review.

"He has since exhausted his petitions and appeals through the immigration courts, the Board of Immigration Appeals, and the U.S. District Court. He will remain in custody pending removal to Trinidad."

The Trump administration has been arresting more immigrants during their periodic check-ins, pointing to their previous deportation orders. The detention of such a prominent activist caused some of Ragbir's supporters to wonder if the government is trying to send a signal.

Das said she'll challenge Ragbir's detention. She said she's been seeking to vacate his criminal conviction while also arguing that it wasn't a deportable offense. She said he was charged with wire fraud while working in a bank and served more than two years in prison, but insists he's innocent.

She also stated that his work on behalf of immigrant New Yorkers is among the reasons he should be allowed to stay.

"When you look at what Ravi has done and the fact that he is an immigrant rights leader, that he speaks with love and compassion for everyone on all sides the system and tries to bring them together, and that he’s giving people hope that we could actually have a more just immigration system, you really have to wonder, why do they want a man like this to leave the country?"

In a statement, Rep. Nydia M. Velázquez (D-NY) denounced the decision to detain Ragbir and said she'd make the case for his release with ICE.

"Not only is this father, family man and community activist being needlessly detained, but these actions by ICE are creating profound fear and distrust among immigrants throughout our City."