SAN DIEGO — The U.S. government kept a database on journalists, activists, organizers and “instigators” during an investigation into last year’s migrant caravan, infuriating civil liberties and media groups who called it a blatant violation of free speech rights.

U.S. Customs and Border Protection compiled information that contained passport photos, date of birth, suspected role in the caravan and whether they had been arrested. The database was revealed Wednesday by the San Diego TV station KNSD.

People listed in the Homeland Security documents provided to the station included 10 journalists, seven U.S. citizens, an American attorney and 47 people from Central America. Some of the people on the list were denied entry into Mexico and had their passports flagged.

The intelligence-gathering efforts were done under the umbrella of “Operation Secure Line,” which was designed to monitor the caravan of thousands of people who began making their way north from Central America late last year to seek asylum in the United States.

The government compiled the database at a time when the caravan was attracting considerable attention in the White House around the midterm elections, with President Trump repeatedly tweeting about the group.

Customs and Border Protection officials didn’t dispute the database, saying in a statement to The Associated Press that extra security followed a breach of a border wall in San Diego on Nov. 25 in a violent confrontation between caravan members and border agents. The confrontation closed the nation’s busiest border crossing for five hours on Thanksgiving weekend.

Officials said it was protocol to follow up on such incidents to collect evidence, and determine whether the event was orchestrated.

Such “criminal events … involving assaults on law enforcement and a risk to public safety, are routinely monitored and investigated by authorities,” the statement said.

The statement didn’t address specifics of why journalists would be on the list to have their passports flagged.

Bing Guan, a freelance journalist and student at the International Center of Photography, said he and a colleague were stopped by U.S. agents while returning from Tijuana in December. A plainclothes agent who didn’t identify his agency showed Guan a multi-page document with dozens of photos and asked him to identify people in the images. The agent then asked Guan to show him the photos he had taken in Tijuana.

Guan said the report of the dossiers confirmed the long-held suspicions he and other journalists had.

“It’s sort of a weird combination of paranoia and pride,” Guan said. “Paranoia because our own government is conducting these intelligence gathering tactics and these patterns of harassment in order to deter journalists from doing their jobs, but also a little bit of pride because I feel like I’m on the right track,” Guan said.

The database was denounced by a variety of groups, including media organizations, the Mexican government, the American Civil Liberties Union, Amnesty International and the Southern Poverty Law Center.

“Monitoring journalists and immigration advocates is outrageous — and if based on their political opinions or legitimate human rights-related activities, as we suspect, it is unlawful,” said Ashley Houghton, tactical campaigns manager for Amnesty International.

The Committee to Protect Journalists called on Congress to investigate what it called a “disturbing pattern of activity,” and representatives from the organization plan to meet with Customs and Border Protection officials to discuss the situation.