MADRID >> A puppet show at an open square in Madrid during Carnival festivities in February featured a policeman who tried to entrap a witch. The puppet officer held up a little sign to falsely accuse her, using a play on words that combined al-Qaida and ETA, the Basque separatist group.

Angry parents complained, and the real police stepped in. They arrested two puppeteers, who could now face as many as seven years in prison on charges of glorifying terrorism and promoting hatred.

Paradoxically, the puppeteers say in their defense, the police proved their point: that Spain’s anti-terrorism laws are being misapplied, used for witch hunts.

Far from an isolated episode, the arrests on Feb. 5 are part of a lengthening string of prosecutions, including two against a rap musician and a poet, that have fueled a debate over whether freedom of protest and speech are under threat in Spain and elsewhere in Europe because of fears of terrorism.

Some European countries, with painful historical chapters of fascism and leftist extremism, have long placed stricter limits on political and hate speech than has the United States. For instance, denying the Holocaust can be prosecuted in Germany as well as France.

But some civil liberties groups and legal experts are growing increasingly alarmed at the broad ways such laws are being adapted as the specter of Islamic extremism becomes Europe’s new preoccupation.

Once such prohibitions become law, even if in response to real security concerns, there is no telling how the statutes could be applied in the future, they say.

The Spanish puppeteers are a case in point. They are being prosecuted under a law on the books in Spain for more than a decade and originally aimed at ETA. Responsible for the deaths of more than 800 Spaniards, the Basque separatist group declared a unilateral cease-fire in 2011.

Last year, however, the conservative government of Prime Minister Mariano Rajoy overhauled and strengthened the law, aiming this time at Islamic terrorism. Among other things, the changes raised the maximum prison sentence for first-time offenders to three years from two to virtually guarantee jail time.

Those steps coincided with the Rajoy government’s introduction of what has become known as a “gag law,” harshly penalizing unauthorized public demonstrations, which has drawn strong criticism at home and abroad.

“This is the latest very serious attack on freedom of expression,” said Joaquim Bosch, a spokesman for Judges for Democracy, an association of about 600 judges that focuses on human rights. “During the Franco dictatorship, troublesome artists went to prison, but not in democratic Spain.”

Even at the height of ETA’s violent campaign, Bosch noted, the law forbidding the glorification of terrorism was used “about two or three times a year.”

Last year, however, judges from Spain’s national court ruled on 25 such cases, absolving the defendants in only six of them. “The politicization of terrorism has been used as a smoke screen to deviate attention from social and corruption problems,” Bosch said.

The widening application of anti-terrorism laws related to speech extends beyond Spain, however, as countries across Europe struggle to balance civil liberties and security in the aftermath of two major terrorist attacks in Paris last year.

Even before those attacks, in November 2014, France reinforced a law similar to that in Spain, which punishes statements praising or inciting terrorism, as worries increased about homegrown radicalization and the influence of extremist groups online.

French lawmakers toughened the penalties — to up to five years in prison and a maximum fine of 75,000 euros (about $82,000), or up to seven years and a $110,000 fine if the statements were made online.

Since the attacks on the satirical newspaper Charlie Hebdo in January 2015, French authorities have aggressively moved to enforce the law and have drawn criticism for rushing to convict people who made provocative statements, sometimes while drunk, that had little to do with actual extremism or terrorism.

In one of the most prominent cases, the comedian Dieudonné M’bala M’bala was convicted and received a two-month suspended prison sentence for a Facebook post that suggested sympathy with one of the gunmen in the Charlie Hebdo attack.

In the view of the Association of Victims of Terrorism, one of the groups in Spain now pressing charges against the puppeteers, their show amounted to an act of “praise and recognition for terrorist organizations that have caused so much pain and suffering within our society.”

Spain’s interior minister, Jorge Fernandez Diaz, also defended the use of the law to arrest the puppeteers at a time when “international terrorism is threatening our country.”

He condemned the show for including other anti-establishment scenes of violence, including the hanging of a judge and the rape of a nun. “To pretend that this is satire or dark humor seems to me an absurdity,” Fernández Díaz said.

But since the arrest of the puppeteers, Raul Garcia Perez and Alfonso Lazaro de la Fuente, street protests have been held in their defense around the country.

The civic associations that organized a demonstration in Granada, where the puppet company was founded, said that “reality supersedes fiction” when artists go to prison for staging a spectacle based on the three-century-old British tradition of Punch and Judy shows, in which puppets were sometimes beaten to death.

Far from promoting terrorism, the Madrid show was intended to condemn “the criminalization of social protest,” the associations said.

According to Eric Sanz de Bremond, a lawyer for the puppeteers, the sign during the show was “used as false incriminating evidence, to prove a crime and never to praise terrorism.” A miniature anarchist notebook that was confiscated by the police was also only a stage prop, he said.

“This is a pure work of fiction and satire,” he said, noting that the puppet show had premiered in Granada “without any incident” in late January.

Inconsistent application, in fact, is one of the dangers of such statutes, said José Ignacio Torreblanca, a professor of political science at the National University of Distance Education.

“I think such laws take us on a dangerous slope toward arbitrariness in a democracy,” he said. “The problem with such a law is that it got drafted in a vague way and there is so little jurisprudence that its application becomes a lottery, dependent on whoever is the judge in the case.”

Ambiguity about where exactly the legal line sits can have its own chilling effect in stifling speech, encouraging self-censorship.

“We have passed such laws without first having a proper debate about where free speech should end,” he said, “so that most Spaniards aren’t now aware of the limits that have been placed and how that can play out in the courts.”

The boundary between terrorism and culture, and the limits of public protest, are being tested in other cases, as well.

Cesar Montana Lehmann, a Spanish singer known as Cesar Strawberry who leads a rap metal band called Def Con Dos, is awaiting trial on accusations of posting offensive messages on Twitter praising terrorism. A public prosecutor wants him sentenced to 20 months in prison.

Aitor Cuervo Taboada, a self-defined revolutionary poet, is set to appear in court Thursday, facing a possible 18-month sentence for publishing writings that the public prosecution says glorify terrorism by praising ETA and offending its victims.

Even before formally taking office last June, Guillermo Zapata was forced to step down as Madrid’s designated councilor for culture for past posts on Twitter in which he offended Jews and a victim of an ETA bombing.

This month, a judge started proceedings to try Zapata for his “cruel humor” comment about the terrorism victim.

Last week, Rita Maestre, spokeswoman for Madrid’s City Hall, appeared in court after being charged with offending religious feelings during a protest held in a university chapel five years ago.

Alongside other protesters, Maestre, who was a student at the time, lifted her top to reveal her bra, while shouting insults against the Catholic Church.

Facing a possible one-year prison sentence, Maestre told the court that it made no sense for a public university in a secular country to maintain a chapel. She expressed regret for causing offense, but insisted that “protests, as long as they are pacific, are legitimate.”

As for the puppeteers, they have not given interviews since spending five days in prison this month.

In a joint statement, however, they insisted the play was not intended to offend but to “tell a story of fiction that unfortunately has many similarities with the reality that we have had to live these days.”

Freedom of speech “isn’t the right to say just what one wants to hear,” the puppeteers argued. “Whoever understands it that way in reality doesn’t believe in it.”

© 2016 The New York Times Company