The police chief in Peoria, Arizona has launched an investigation into what activists are calling a "de facto immigration checkpoint" that nabbed young immigrants attending a speech President Barack Obama delivered on immigration reform last month.

"It was a de facto immigration checkpoint," Respeto executive director Lydia Guzman recently explained to KPNX.

According to police, the checkpoint began as an effort to inspect commercial vehicles, but Immigration and Custom Enforcement (ICE) officers showed up voluntarily.

"We have an email list and that goes out to all the agencies -- law enforcement, different agencies," police spokesperson Amanda Jacinto said. "ICE happens to be one of the people on that list."

ICE, however, insisted that its agents attended the checkpoint at the request of the Arizona Department of Transportation, which had partnered with Peoria police.

Authorities said that 11 undocumented immigrants were detained during the three-day checkpoint operation. Ten of those detainees had been released by Tuesday.

Lino Garcia Paulino was detained as he was driving back from Phoenix with his pregnant wife. He spent a week in jail before a friend was able to pay the $3,000 for his bail. Paulino's wife was released after telling officers she was in the process of applying for citizenship.

Coincidentally, the checkpoint kicked off on Jan. 29, the same day that President Obama was speaking about immigration reform in nearby Las Vegas, and some of the young immigrants -- or DREAMers -- who attended his speech were also caught up in the operation.

"We thought the timing of this was very suspicious," Guzman observed. "We thought that maybe this was some sort of way to antagonize the activist groups that went out to the president's speech."

For its part, the Peoria Police Department almost immediately denied allegations of racial profiling, but hours later promised to review activists' complaints.

"It was in no way ever intended to be, set up to be or in any way was a immigration check point," Jacinto declared. "At no point were our officers involved in any sort of racial profiling."

Peoria Police Chief Roy Minter on Monday announced that the department would conduct an official inquiry to find out why officers decided to stop private motorists during a checkpoint that was set up to inspect commercial vehicles.

"That operations plan did not state anything about a vehicle registration compliance checkpoint," he noted.

Police said that the 17 vehicles impounded during the operation would be given back to the owners and all fees would be waived as a "gesture of good will."

Watch this video from KPNX, broadcast Feb. 11, 2013.