An immigrant mother who was granted leniency under the Obama administration has been deported to Mexico, providing an early example of how U.S. President Donald Trump will carry through on his campaign promises on immigration.

The lawyer for Guadalupe Garcia de Rayos and an immigrant advocacy group say they learned from Mexican diplomats in the U.S. that she had been taken back to Mexico.

The 36-year-old Phoenix mother was in the country illegally and checked in Wednesday for what she thought was a routine meeting with Immigration, Customs and Enforcement (ICE) officials.

They then moved to deport her, prompting protests. Seven people were arrested after they blocked ICE vans from leaving an office near central Phoenix.

Immigration officials detain woman after she reports for check-in 0:45

The Arizona Republic newspaper says that Rayos apparently was in one of the vehicles, which are used to transport people in ICE custody to detention centres or to the border for deportation.

After 9 p.m., police officers amassed on the south side of the facility as protesters continued to block access, chanting "Justice!" and "Power to the people, no one is illegal!"

Besides the few people engaged in criminal acts, most people out here are peaceful and exercising their rights properly. —@phoenixpolice

'We're living in ... an era of war on immigrants'

Puente Arizona, an immigrant advocacy group, said Rayos came to the U.S. as a 14-year-old and now has two children. She was arrested on Wednesday while reporting, as required, to ICE.

The activists said it was an attempt by Trump's administration to deport immigrants living in the country illegally who had previously not been a priority for deportation under the Obama administration.

Her arrest came just days after the Trump administration broadened regulations under which some people will be deported.

Phoenix police said about seven people were arrested. They added that the protest was mostly peaceful. (Rob Schumacher/The Arizona Republic/Associated Press)

"We're living in a new era now, an era of war on immigrants," Rayos's lawyer, Ray A. Ybarra Maldonado, told the New York Times.

Phoenix station KTAR reported that she was arrested in 2008 during a workplace raid and was later convicted of felony identity theft for possessing false papers. Despite her conviction, she was allowed to live in Arizona and checked in with ICE officials every six months.