An immigrant activist in Arizona who tried to obstruct the arrest of another immigrant was himself arrested, sparking an outcry among other activists.

Raul Alcaraz Ochoa, an organizer of day laborers, lay down beneath a U.S. Border Patrol vehicle in an unsuccessful bid to thwart the arrest of another man in Tucson, authorities said Monday.

Ochoa was pepper-sprayed by a Border Patrol agent Sunday after he refused to come out from underneath the vehicle, Tucson police spokesman Fabian Pacheco said.

Alcaraz was protesting the arrest of a driver whose vehicle was pulled over after officers got a call from someone who reported two children being put into a car trunk, Pacheco said.

Police were concerned about the possibility of a child abduction.

Immigrant rights supporters planned a rally outside a Tucson police building to protest the arrests of Alcaraz and the driver.

Driver Rene Huerta Meza, 30, was handcuffed as officers who made the stop investigated further and discovered a woman and five children in the two-door hatchback.

A 7-year-old girl and two 4-year-old boys in the vehicle were Meza's children, while the woman was the mother of two other 4-year-old boys.

Officers learned that none of the children was restrained inside the vehicle and found two children in the vehicle's hatchback area, Pacheco said.

Police said they learned that Meza's driving privileges had been suspended after he presented a Mexican voter registration card as a form of identification. He was cited for civil child restraint violations and for having a suspended driver's license, a criminal offense.

Meza's arrest for prompted an immigration status check. The check is required under a section of Arizona's 2010 immigration law that says authorities must verify the immigration status of all arrested people, Pacheco said. Meza is undocumented, according to the Arizona Daily Star.

Pacheco said Alcaraz, who is a legal permanent resident, then started to interfere with officers, telling them that authorities were tearing apart families in arresting undocumented immigrants.

The Border Patrol didn't immediately return a message seeking comment on the arrests.

Alcaraz said he lay down beneath the vehicle and refused to come out because he saw the children in the car crying as their father was put into a police car. He said he thrust himself into the situation because he sees Latinos getting harassed by authorities on a regular basis and he's tired of the injustice.

The Star said that Meza Ochoa was released from custody Monday, but faces charges of interfering with a federal officer.

Based on a story by The Associated Press.

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