Gen. Eric Smith, the commandant of the Marine Corps, told the Senate Armed Services Committee that the 700 Marines being sent to Los Angeles received crowd control training in Twentynine Palms, California.

Sen. Richard Blumenthal, D-Conn., expressed his doubts about the use of combat-trained units domestically, saying he was "deeply worried" that their deployment increased the risk of lethal force possibly being used.

Smith said he’s not concerned, adding, "I have great faith in my Marines."

Smith said the Marines -- who are equipped with shields and batons -- do not have arrest authority but will be providing support to law enforcement protecting federal property and personnel.

Sen. Elissa Slotkin, D-Mich., asked Smith if he knew how much crowd control training Marines receive. Smith said he didn't have the precise number but said it was "in excess of two hours," calling it "a standard annual training in the use of non-lethal means."

Slotkin noted that the police forces on the street receive 600 hours of crowd control training.

-ABC News’ Luis Martinez

During Defense Secretary Pete Hegseth’s testimony on Capitol Hill, Rep. Betty McCollum, the top Democrat on the House Appropriations Defense Subcommittee, asked the cost of sending Marines and the National Guard to Los Angeles and what resources were being taken away by the move, but Hegseth repeatedly did not answer the question.

Hegseth said ICE “has the right to safely conduct operations in any state and any jurisdiction in the country," and drew comparisons to the 2020 George Floyd protests.

"ICE ought be able to do its job, whether it's Minneapolis or Los Angeles," he said.

"We have deployed National Guard and the Marines to protect [ICE] in the execution of their duties, because we ought be able to enforce integration immigration law in this country," he said.

McCollum insisted the Marines aren’t trained for a domestic mission but Hegseth insisted they were.

-ABC News’ Ivan Pereira and Anne Flaherty

More than 100 people were arrested on Monday night in Los Angeles, as "fringe groups" continued late-night protests, City of Los Angeles Mayor Karen Bass said.

"What we're seeing downtown is just horrible, but you know that the majority of people that attended the protest this afternoon were peaceful," Bass told ABC News' KABC station in a phone interview late Monday night.

She said the more-violent protesting and vandalism were happening "late at night," adding that she assumed violent protests weren't being led by people supporting immigrants, but rather by "fringe groups."

"It's my understanding that over 100 people have been arrested tonight, the majority of them for unlawful assembly," she said.

She said each of those who were arrested would be "evaluated," including checking to see whether they have active warrants.

"But, again, this has nothing to do with the protests that happened earlier this afternoon," Bass said. "That was a protest -- fighting for the rights of immigrants and calling for the raids to stop."

The Federal Bureau of Investigation has identified a man who is wanted for throwing rocks at police and law enforcement vehicles during the protest in Paramount, California, on Saturday.

The suspect has been identified as 40-year-old Elpidio Reyna, from nearby Compton, and is wanted for assault on a federal officer, according to the FBI

The FBI is offering a reward of up to $50,000 for information about the suspect, leading to his arrest and conviction.

The incident happened at approximately 3:30 p.m. on Saturday, according to the FBI, when the suspect threw rocks at law enforcement vehicles on Alondra Boulevard in Paramount, injuring a federal officer and damaging government vehicles.