WASHINGTON — The Justice Department said on Wednesday that it was investigating juvenile correctional facilities in Texas over allegations of physical violence, sexual abuse and other mistreatment of children held there.

The investigation, which will also examine the state’s use of isolation and chemicals like pepper spray, is part of a broader effort to overhaul the criminal justice system and address conditions in prisons, a goal that in recent years has had bipartisan support and was pursued by the Obama and Trump administrations before President Biden took office. And it follows other recent Justice Department investigations into adult correctional facilities in states including Georgia and New Jersey.

“Prison conditions and the conditions inside of institutions where young people are detained is a priority issue for the Civil Rights Division at the Justice Department,” Kristen Clarke, who leads the division, said at a news conference.

“No child who was sent to a Texas facility for treatment and rehabilitation should be subjected to violence and abuse, nor denied basic services,” she said.

The department opens its inquiries into correctional facilities based on public documents, news reports, social media posts and conversations with people involved in local prison systems that reveal instances of brutal violence and sexual abuse, neglect of the mentally ill, and other serious improprieties.

Ms. Clarke said that the Justice Department investigation into Texas’ five secure juvenile facilities came after at least 11 staff members were arrested and accused of sexually abusing the children in their care, with one arrest as recently as last week. Other staff members reportedly shared pornography with children and paid them in cash and drugs to assault their peers.

“There are also reports of staff members’ use of excessive force on children, including kicking, body-slamming and choking children to the point of unconsciousness,” Ms. Clarke said. She added that there was also an incident last February in which “a staffer reportedly pepper-sprayed a child and placed him in full mechanical restraints, including handcuffs, a belly chain, shackles and a spit mask, and then body-slammed him onto a bed.”

Ms. Clarke said the number of children and teenagers with serious self-injuries in Texas’ secure facilities in 2019 more than doubled from the previous year, and that at least two possible suicides were reported in recent years.

The Texas Juvenile Justice Department, which oversees one of the nation’s largest networks of youth correctional facilities, said that it would fully cooperate with the investigation.

“We all share the same goals for the youth in our care: providing for their safety, their effective rehabilitation, and the best chance for them to lead productive, fulfilling lives,” Camille Cain, the executive director of the Texas department, said in a statement.

While the U.S. Justice Department and Gov. Greg Abbott of Texas, a Republican, have opposed each other on several high-profile issues, including the state’s new law banning nearly all abortions, they have both sought to address the problems with the state’s juvenile prisons.

In July, Mr. Abbott asked the Texas Rangers, a division of the state’s Department of Public Safety, to investigate Juvenile Justice Department staff members over allegations of illegal conduct with incarcerated children.

“Child welfare is a bipartisan issue, and that makes it possible to see reform in a politically divided state,” said Brett M. Merfish, the director of youth justice at Texas Appleseed, a criminal justice and legal aid group.

Texas Appleseed worked with another group, Disability Rights Texas, on a complaint that detailed staff-on-youth sexual assault, physical abuse and gang activity at the facilities, as well as chronic understaffing and inadequate mental health care.

The advocacy groups sent their complaint to the Justice Department last fall, and Ms. Merfish said that she was encouraged by the investigation and hoped it signaled the beginning of real change.

“This isn’t a new problem in Texas,” Ms. Merfish said.

Chad E. Meacham, the acting U.S. attorney for the Northern District of Texas, said that many children are already traumatized when they enter the Texas criminal justice system.

Of the children who arrive at a complex for girls in his district, 86 percent have already survived domestic violence, parental substance abuse or mental illness, Mr. Meacham said. About 63 percent of the girls are immediately placed on suicide watch and more than 90 percent are deemed at risk of sexual exploitation, he said.

“We cannot expect them to thrive once they get out if they emerge from confinement after they’ve been traumatized by sexual abuse, excessive force or incessant isolation,” Mr. Meacham said.

The Justice Department investigation will focus on whether there is a pattern or practice of physical or sexual abuse of children in the Texas facilities, and whether there is a pattern or practice of harm resulting from the excessive use of chemical restraints like pepper spray, excessive use of isolation or a lack of adequate mental health services.

If investigators find evidence of violations, the department could mandate reforms.

Last month the Justice Department opened an investigation into unconstitutional abuses of prisoners in Georgia, prompted by allegations and videos of violence in facilities across the state and a riot at one prison that played out on social media.

The Justice Department has recently imposed reform plans on state prisons in Virginia and New Jersey.