PARIS — German authorities canceled right-wing protests Sunday, citing threats, and Belgian officials said they were still searching for the ringleader of a terrorist cell as Europe continued to grapple with the aftermath of extremist attacks in Paris.

Meanwhile, French police said they had released three women who were among 12 people arrested last week in an anti-terrorism sweep in the Paris suburbs connected to the attacks that killed 17 people this month.

“They didn’t play a direct role in the attacks,” French police union spokesman Christophe Crepin said.

Also Sunday, a French court halted a rally by anti-Islamic groups in Paris, finding they were promoting Islamophobia, according to France’s BFM TV.

In Germany, police banned a scheduled rally by Patriotic Europeans Against Islamization of the West, or PEGIDA, and other public gatherings in the eastern city of Dresden, citing a threat against the right-wing populist group. Organizers said a death threat had been posted on Facebook, according to the local newspaper Dresdner Neueste Nachrichten.

The attacks on the satirical newspaper Charlie Hebdo and on a kosher grocery in Paris have prompted soul-searching and massive investigations in Europe, and focused attention on other, apparently unrelated terror cells, including one raided in Belgium.

Officials had been investigating possible ties between four men stopped Saturday in Greece and the cell in Belgium. Belgian officials said Sunday that the four did not include the ringleader they are seeking, Abdelhamid Abaaoud, 27, a Morroccan raised in Belgium who left to join Islamic State militants in Syria.

However, they asked that one of the suspects be extradited, according to BFM TV.

Belgian police have charged five of the 13 people who were detained last week, releasing two, according to Radio Television Belge Francophone. The arrests were part of a massive sweep that left two dead Thursday after a firefight with police in the eastern city of Verviers and stopped a “large-scale” attack hours before it was due to occur, federal prosecutors said.

Hundreds of Belgian soldiers took to the streets over the weekend to protect potential terrorist targets.

Italy has expelled nine suspected terrorists since late December, some of whom had joined the Islamic State.