The mayor of Portland, Oregon, asked the city’s police chief to investigate “disturbing” text messages sent between a police lieutenant and the leader of a far-right group that organized rallies attended by violent extremists.

The texts, published Thursday by the Willamette Week, show that Portland’s commander for the police rapid response team, Jeff Niiya, was in communication with Joey Gibson, leader of a group called Patriot Prayer, as Gibson organized far-right demonstrations in 2017 and 2018. Their texts were described as “friendly” and sometimes joking.

In one exchange from December 2017, Niiya asked Gibson about his companion’s arrest warrant. The man in question frequently fights antifascist protesters and has allegedly assaulted bystanders, according to the Week. “Just make sure he doesn’t do anything which may draw our attention,” Niiya responded. “If he still has the warrant in the system (I don’t run you guys so I don’t personally know) the officers could arrest him. I don’t see a need to arrest on the warrant unless there is a reason.” He also said that officers had ignored the warrant at a previous protest.

“The released text messages, which I learned about in today’s Willamette Week, are disturbing,” Portland Mayor Ted Wheeler said in a statement. “It is imperative for law enforcement to remain objective and professional, and in my opinion, these text messages appear to cross several boundaries. They also raise questions about whether warrants are being enforced consistently and what information is being shared with individuals who may be subject to arrest.”

A police spokeswoman told the Week that it was “not uncommon for officers to provide guidance for someone to turn themselves in on a warrant if the subject is not present.” She added: “In crowd management situations, it may not be safe or prudent to arrest a person right at that time, so the arrest may be delayed or followed up on later.”

According to the Week, Niiya also told Gibson where unrelated leftist protests were taking place, and the two joined in complaining about a reporter from the Oregonian. The two even talked about Gibson running for office, an idea that prompted Niiya to tell Gibson, “Good for you.”

Gibson’s group, Patriot Prayer, organized rallies in the wake of President Trump’s election in which far-right protesters clashed with antifascist groups. One man who associates with Patriot Prayer, Jeremy Christian, has been accused of fatally stabbing two men who were trying to protect a pair of black women from Christian’s anti-Muslim rants on a Portland metro train.

A member of the city council first called for an investigation. “This story, like many that have come before it, simply confirms what many in the community have already known,” Commissioner Jo Ann Hardesty said in a statement. “There are members of the Portland police force who work in collusion with right-wing extremists.”