CHICAGO — Three activists who traveled to Chicago for a NATO summit were accused Saturday of manufacturing Molotov cocktails in a plot to attack President Barack Obama’s campaign headquarters, Mayor Rahm Emanuel’s home and other targets.

But defense lawyers shot back that Chicago police had trumped up the charges to frighten peaceful protesters away, telling a judge it was undercover officers known by the activists as “Mo” and “Gloves” who brought the firebombs to a South Side apartment where the men were arrested.

“This is just propaganda to create a climate of fear,” Michael Deutsch said. “My clients came to peacefully protest.”

On the eve of the summit, the dramatic allegations were reminiscent of previous police actions ahead of major political events, when authorities moved quickly to prevent suspected plots but sometimes quietly dropped the charges later.

Prosecutors said the men were self-described anarchists who boasted weeks earlier about the damage they would do in Chicago, including one who declared, “After NATO, the city will never be the same.”

At one point, one of the suspects asked the others if they had ever seen a “cop on fire.”

Police Superintendent Garry McCarthy dismissed the idea that the arrests were anything more than an effort to stop “an imminent threat.”

“When someone was in the position (of having) Molotov cocktails — that’s pretty imminent,” he said. “It was not a completed investigation.”

The men allegedly bought fuel at a gas station for the makeshift bombs, poured it into beer bottles and cut up bandanas to serve as fuses.

The suspects are Brian Church, 20, of Ft. Lauderdale, Fla.; Jared Chase, 24, of Keene, N.H.; and, Brent Vincent Betterly, 24, of Oakland Park, Fla.

If convicted on all counts — conspiracy to commit terrorism, material support for terrorism and possession of explosives — the men could get up to 85 years in prison.

Outside the courtroom, Deutsch said the two undercover police officers or informants were also arrested during the Wednesday raid, and defense attorneys later lost track of the two.

“We believe this is all a setup and entrapment to the highest degree,” Deutsch said.

The suspects were each being held on $1.5 million bond. Six others arrested Wednesday in the raid were released Friday without being charged.

The three who remained in custody apparently came to Chicago late last month to take part in May Day protests. Relatives and acquaintances said the men were wanderers who bounced around as part of the Occupy movement and had driven together from Florida to Chicago, staying with other activists.

Court records indicated no prior violent behavior.

Longtime observers of police tactics said the operation seemed similar to those conducted by authorities in other cities before similarly high-profile events.

For instance, prior to the Republican National Convention in 2008 in St. Paul, Minn., prosecutors charged eight activists who were organizing mass protests with terrorism-related crimes after investigators said they recovered equipment for Molotov cocktails, slingshots with marbles and other items.

The protesters, who became known as the RNC Eight, denied the allegations and accused authorities of stifling dissent. The terrorism charges were later dismissed. Five of the suspects eventually pleaded guilty to misdemeanor charges, and three had their cases dismissed altogether.

Molotov cocktails are dangerous weapons, but it “kind of stretches the bounds to define that as terrorism,” said Michael Scott, director of the Center for Problem-Oriented Policing at the University of Wisconsin-Madison.

He said police have a history of abusing such tactics, sometimes infiltrating purely peaceful protest groups to search for troublemakers.

But if the allegations are true, police were justified in moving quickly to take the men off the streets, even if the terrorism charges don’t stick.

Just one week before their arrest, at least two of the suspects were involved in a minor confrontation with police captured on a video that was then posted on YouTube and aired widely by Chicago media, said another defense attorney, Sarah Gelsomino.

The men had been stopped by police after turning their car into a private driveway.

In the video, one officer asks another what Chicago police would have said in 1968 when they clashed with demonstrators at the Democratic National convention.

“Billy club to the … skull,” the officer responds. Another officer says to the men in the car, who the police take as protesters, “We’ll come look for you.”

Documents filed by prosecutors in support of the charges in Chicago painted an ominous portrait of the men, saying the trio also discussed using swords, hunting bows and knives with brass-knuckle handles in their attacks.

Relatives and acquaintances painted a starkly different picture.

Activist Bill Vassilakis, who said he let the men stay in his apartment, described Betterly as an industrial electrician who had volunteered to help with wiring at The Plant, a former meatpacking facility that has been turned into a food incubator with the city’s backing.

“All I can say about that is, if you knew Brent, you would find that to be the most ridiculous thing you’ve ever heard. He was the most stand-up guy that was staying with me. He and the other guys had done nothing but volunteer their time and energy,” he said.

Betterly appears to have a history of minor run-ins with law enforcement.

Earlier this year, he was cited for disorderly intoxication in February in Miami-Dade County, Fla., but the case has been dismissed, according to online court records.

Authorities in Oakland Park, Fla., said Betterly and two other young men walked into a public high school last fall after a night of tequila drinking and took a swim in the pool, according to a report in the South Florida Sun-Sentinel.

They stole fire extinguishers from three school buses, discharged one and smashed a cafeteria window with another. The vandalism caused about $2,000 in damage. Betterly was charged with burglary, theft and criminal mischief, the newspaper said.

Chase grew up in Keene, N.H., and moved to Boston a few years ago before becoming active in the Occupy movement, said his aunt, Barbara Chase of Westmoreland, N.H.

Jared Chase’s father, Steve Chase, died about five weeks ago after a long struggle with a disease that left him disabled, Barbara Chase said. The family had been waiting for him to come home before having a funeral.

She said she was stunned to learn of the charges against her nephew.

“That surprised me because he’s not that dumb,” said Barbara Chase. “He always seemed harmless, but who knows? Outside influences sometimes can sway people to do things that they normally wouldn’t do.”

Elsewhere around Chicago, demonstrations remained relatively small. Scattered groups of protesters gathered in some neighborhoods, including several hundred who marched to the mayor’s house.

Late in the day, another group gathered in the Loop business district and marched down the city’s famous Michigan Avenue. Police on horseback and bicycle kept them away from diners at outdoor cafes who ventured downtown despite wide-ranging security precautions.

The largest protests were expected Sunday, when thousands of people were expected to march from a band shell on Lake Michigan to the McCormick Place convention center, where NATO delegates will meet.