Dozens of people gathered in downtown Dallas outside City Hall on Sunday to voice their opposition to the state's new sanctuary cities law, which Gov. Greg Abbott signed off on last week.

A similar protest was planned for Sunday in Austin, where hundreds marched from City Hall to the Governor's Mansion, the Texas Observer reported.

The law, set to take effect Sept. 1, will punish cities, counties and universities that prohibit local law enforcement officers from asking about a person's immigration status or enforcing immigration law. It will create a criminal charge for police chiefs, county sheriffs and constables who violate the ban and would fine local jurisdictions up to $25,000 a day for each violation.

A provision in the law will also allow police to question anyone they detain about their immigration status.

Familias protestan vs. la #SB4 en #Dallas y celebran Día de las Madres. pic.twitter.com/uRwioTUXP1 — HOY DALLAS (@HOYdallas) May 14, 2017

Abbott and advocates of the legislation say it will get criminals who are in the country illegally out of Texas. But critics worry that it may be unconstitutional and say that it condones racial profiling and will alienate immigrants who fear their families will be disrupted by deportation.

Hundreds gather outside Dallas City Hall to oppose SB4 pic.twitter.com/pLIpiG5Hb4 — Gabriel Roxas (@gabriel__roxas) May 14, 2017

Dallas activist Carlos Quintanilla said he began organizing Sunday's rally at City Hall with Accion American once Abbott signed the sanctuary cities bill into law a week ago.

He said he hoped the event will help build momentum for the effort to vote out Abbott in 2018.

"He needs to soften his heart because we aren't all drug dealers and criminals. We respect laws," Quintanilla said. "We want to be a greater part of Texas. Immigrants work in jobs no one wants."

The group plans to protest once a month and eventually visit the Governor's Mansion.

Dallas resident Erika Ibar said she attended the Mother's Day protest because of her children.

"I came for my kids, my family, for everything," the mother of three said. "I'm very worried about the police and the government."

The law has already been challenged in court. The tiny border town of El Cenizo is the first city to sue the state over the new ban.