WASHINGTON—The U.S. government has criminally charged David Huerta, president of the Service Employees International Union (SEIU) of California, for allegedly conspiring to obstruct an immigration-related detention in Los Angeles.

On June 6, Huerta allegedly conspired with other protesters to share the location of a site where Immigration and Customs Enforcement (ICE) special agents had arrived to conduct a search warrant of businesses purportedly employing illegal immigrants without authorization.

When he arrived at the location, Huerta allegedly sat down in front of an ICE vehicle to obstruct its path and encouraged others to do so, according to the criminal complaint filed against him in the U.S. District Court for the Central District of California.

“HUERTA and another person sat cross legged in front of the vehicular gate. HUERTA waved at those around him and yelled ‘everybody sit down, sit down!’ ... HUERTA also yelled to the protestors ’stop the vehicles,'” an affidavit filed in support of the complaint reads. Huerta was arrested after allegedly sitting down in front of a white police van that attempted to enter the site, allegedly preventing it from entering the property.

Los Angeles has been rocked by three days of riots and protests directed against federal immigration enforcement efforts. President Donald Trump activated the National Guard to quell the riots despite California Gov. Gavin Newsom’s opposition to the deployment. The state filed a lawsuit against the Trump administration on June 9, alleging that the deployment was illegal.

At least 21 protesters had been arrested as of the night of June 8, according to the Los Angeles Police Department.

The criminal complaint alleges that Huerta was taunting federal agents at the site.

“HUERTA was also yelling at me and other officers, at one point screaming ‘explain to me, you want to go [expletive] speak with your [expletive] face’ and reaching through the gate to gesture with his arm,” Ryan Ribner, a special agent with the Department of Homeland Security, was quoted in the complaint. “HUERTA also yelled to the protestors ’stop the vehicles.'”

Huerta has been charged with one count of a “conspiracy to impede an officer” under Title 18, U.S. Code Section 372. The offense carries a maximum penalty of six years in prison, as well as a fine. Video footage of Huerta’s activity was shared on social media by Bill Essayli, the interim U.S. Attorney whose office is leading the prosecution.

Some Democratic elected officials and labor groups criticized Huerta’s arrest and called for his release.

“The violent assault and arrest of California SEIU President David Huerta is unacceptable. Mr. Huerta should be released immediately and all charges dropped,” U.S. House Minority Leader Rep. Hakeem Jeffries (D-N.Y.) wrote in a statement.

The American Federation of Labor and Congress of Industrial Organizations (AFL-CIO) also commented on the arrest in a statement, saying: “As the Trump administration’s mass deportation agenda has unnecessarily targeted our hard-working immigrant brothers and sisters, David was exercising his constitutional rights and conducting legal observation of ICE activity in his community.

“The labor movement stands with David and we will continue to demand justice for our union brother until he is released.”