Baraka has clashed with federal immigration officials ever since the detention facility, privately owned by the GEO Group, opened. Friday’s arrest was a culmination of the back-and-forth, with Newark officials repeating that the owner has not cooperated with local code inspectors.

Ras Baraka, the Democratic mayor of Newark, New Jersey, was arrested on Friday while joining members of Congress at an Immigration and Customs Enforcement detention center, according to interim U.S. Attorney for the District of New Jersey Alina Habba.

An immigration detention center in New Jersey is at the center of tensions between three congressional Democrats and the Trump administration after the arrest of Newark’s mayor set off a scrum outside the complex.