BRUSSELS - Europe was on high alert on Monday as the suspected mastermind of a jihadist cell in Belgium remained at large and jittery authorities blocked anti-Islamist rallies in Germany and France.
In the wake of the deadly attacks in France and anti-terror raids in Belgium, EU foreign ministers are to meet in Brussels to discuss ways to boost cooperation to combat the threat posed by radicalised Europeans returning home after fighting in Iraq and Syria.
The meeting Monday comes as the bloc prepares for a special leaders' summit on February 12 dedicated to fighting terrorism.
With tensions heightened, the second gunman in the attack on Charlie Hebdo magazine which killed 12 people was buried discreetly in an unmarked grave near Paris late Saturday in the hope that it would not become a pilgrimage site for radical Islamists.
Meanwhile, Abdelhamid Abaaoud, considered the brains behind the cell plotting to kill Belgian police, was still on the run days after the group was dismantled by intelligence services.
But the probe appeared to be progressing with Belgian federal prosecutors announcing they would seek the extradition of a suspect arrested in Athens on Saturday "who could be linked" to the cell.
In Germany, police banned a rally by the anti-Islamic PEGIDA movement and other open-air gatherings planned for Monday in the eastern city of Dresden, saying there was a "concrete threat" of an attack against its leadership.
The group claimed the threat came from the Islamic State group based in Syria and Iraq, with local media reporting that PEGIDA's most prominent leader Lutz Bachmann was the target.
The PEGIDA marches have grown steadily since they began in October and drew a record 25,000 people last Monday in the wake of the Paris attacks that left 17 people dead.
The anti-Islamic rallies have spread to other European countries as well, with the first Danish PEGIDA march to take place in Copenhagen on Monday. Organisers said they were expecting some 300 people.
Separately, a French court on Sunday prevented a rally by anti-Islamist groups in Paris on the grounds that they were promoting Islamophobia.
Meanwhile in a New York Times op-ed, French far-right leader Marine Le Pen urged the government to denounce as "Islamists" the perpetrators of the Paris attacks.
"France, land of human rights and freedoms, was attacked on its own soil by a totalitarian ideology: Islamic fundamentalism," Le Pen wrote.
Cherif Kouachi, one of two brothers who attacked satirical weekly Charlie Hebdo on January 7, was buried in Gennevilliers, a day after the funeral of his older brother Said in the northeastern city of Reims.
The family, including Cherif Kouachi's widow, kept away from the funeral, the mayor's office said.
The brothers were shot dead by police after a three-day manhunt following their attack on Charlie Hebdo, which had enraged many Muslims around the world with its repeated publication of cartoons lampooning the Prophet Mohammed.
Anger erupted in a string of majority Muslim countries after the magazine responded to the attack by running another caricature last week, showing the prophet under the headline "All Is Forgiven".
The worst unrest was in Niger, where at least 10 people were killed and several churches torched over two days of rioting.
Fresh protests broke out Sunday in Pakistan where thousands gathered in almost all major cities, including Lahore, Karachi and Islamabad, chanting angry slogans and burning French flags.
Charlie Hebdo's chief editor has defended the cartoons.
"Every time we draw a cartoon of Mohammed, every time we draw a cartoon of prophets, every time we draw a cartoon of God, we defend the freedom of religion," Gerard Biard told NBC's "Meet the Press" programme.
The weekly has sold 2.7 million copies of the post-killings "survivors' issue" in France alone and said it would extend its print run to seven million copies -- exponentially more than the weekly's normal circulation of 60,000.
President Francois Hollande said France was committed to freedom of expression and people should not change their habits since "to do so would be to yield to terrorism".
But a poll published in Le Journal du Dimanche found 42 per cent of French people thought publications should avoid running cartoons of Mohammed, and 50 per cent favoured limiting freedom of expression on the Internet and social networks.
French police were meanwhile still questioning nine people arrested Friday on suspicion of providing logistical support to Amedy Coulibaly, another Islamist gunman who claimed to be working with the Kouachi brothers.
Coulibaly killed four Jews in a siege at a Paris kosher supermarket on January 9 before being shot dead by police.