French authorities have detained 54 people for “defending terrorism” in the aftermath of the Charlie Hebdo shootings, it was announced Wednesday, as the satirical magazine’s “survivor” issue sold out in a predawn rush for copies.

The print run for the weekly magazine was increased to 5 million after a rush for the post-attack edition — 2 million more than initially planned.

Meanwhile a clampdown by police resulted in dozens of arrests, including that of controversial comedian Dieudonné M'Bala M’Bala, who goes by the name Dieudonné. The comic, whose routines have featured an arm gesture that resembles a Nazi salute, has been fined repeatedly for hate speech. His provocative performances were banned last year, but he has a core following among a segment of France's disaffected youth.

In a Facebook post that was swiftly deleted, Dieudonné said he felt like "Charlie Coulibaly" — merging the names of Charlie Hebdo and Amedy Coulibaly, the gunman who seized a kosher market and killed four hostages and a policewoman last week. In a separate post on Monday afternoon, the comic wrote an open letter to France's Interior Minister Bernard Cazeneuve. "You are looking for a pretext to forbid me. You consider me like Amedy Coulibaly when I am not any different from Charlie," Dieudonné wrote.

Coulibaly apparently coordinated his attack with Saïd Kouachi and Chérif Kouachi, the brothers who stormed the offices of Charlie Hebdo, killing 12 people, including three policemen. Charlie Hebdo, a satirical Paris weekly, had published cartoons of the Prophet Muhammad — considered an insult to Islam. In a video posted posthumously, Coulibaly claimed allegiance to the Islamic State of Iraq and the Levant. The Kouachis said during the attack that they were sent by Al-Qaeda’s affiliate in Yemen; AQAP’s leader claimed responsibility in a video released on Wednesday.

The attacks have prompted France to tighten security measures against attacks, but none of the 54 people detained are suspected of planning violence or having links to last week’s attacks, which could raise questions about whether the government is impinging on freedom of speech.

Last week in a Washington Post op-ed titled "The biggest threat to French free speech isn’t terrorism. It’s the government," George Washington University professor Jonathan Turley argued that the French have been "leading the Western world in a crackdown on free speech."

He referred to bans on Dieudonné performances — even before his arrest on Wednesday — saying, "It is easy to silence speakers who spew hate or obnoxious words, but censorship rarely ends with those on the margins of our society."

The Justice Ministry said that 54 people, including four minors, have been detained for defending or verbally threatening terrorism since the Charlie Hebdo attack. Several have already been convicted under special measures for immediate sentencing.

Justice officials are holding meetings with the defendants to remind them that defending terrorism is illegal. Like many other European countries, France has strong laws against hate speech, particularly anti-Semitism, in light of its history during World War II.

The French government is working on new measures to expand phone tapping and other surveillance efforts against attacks, which it hopes to have in place by next week, government spokesman Stéphane Le Foll said Wednesday.

Separately, the French government is launching an effort to rethink its systems of education, urban policy and integration for immigrants — a response to critics who say last week's attacks reveal deeper problems of inequality among second- and third-generation immigrants in the banlieues, the neglected suburbs of Paris.