BRUSSELS -- After a four-day shutdown prompted by a threat alert across Brussels, schools are reopening with the help of beefed-up security, including police armed with machine guns.
Investigators also sought fresh leads in the manhunt for a key suspect in the Nov. 13 Paris attacks after acknowledging that Belgian authorities let him slip through just hours after the attacks.
Though the Belgian capital continues to be under the highest-level threat alert, meaning that an attack is serious and imminent, schools and subways began reopening across the city Wednesday. That is restoring a sense of normality to the city, parts of which have been deserted since the alert was first raised to the top level Saturday.
The threat level is expected to be in place until at least Monday unless there are significant developments, such as the capture of suspects linked to the Paris attacks.
At Brussels' College Saint-Jean-Berchmans, some parents gave their children a quick kiss before dropping them off, while several police officers guarded the entrance, including one holding a machine gun. Among the students at the school is Belgium's Princess Eleonore.
"I'm concerned, but I think that life must go on," said Dimitri De Cra Yencour, a father of four. "Even if something happens in Paris or in Brussels, they have to go back to school," he said, adding he had instructed his children to be extra attentive and to tell their teachers if they saw anything unusual.
At other schools in the region, officials sent to parents letters and emails explaining security measures taken under police orders, such as limiting access to the school and not allowing children to play or gather in large spaces like courtyards.
The Rev. Didier Nkoy Balengola said he had explained to his children that "there are some bad men who for no reason want to hurt innocent people" but that he had confidence in the police.
Others said that after the terrorism-sparked school vacation this week, it was time for classes to restart.
"It was like Christmas come early for the children," said Annalaure Leger, a mother of two. "They stayed at home and played with the neighbors' kids."
Leger said neither she nor her children were too concerned about an imminent attack.
"It would be better if the police had caught the terrorists, but the children know they are trying to do that so that everyone is safe."
In Washington, President Barack Obama said there currently is no "specific and credible" intelligence indicating a terrorist plot on the United States, as he sought to reassure anxious Americans for the Thanksgiving holiday.
Speaking Wednesday at the White House, Obama said it was understandable that Americans might be nervous after the attacks in Paris, but he urged people to go about their normal activities around Thanksgiving.
"While the threat of terrorism is a troubling reality of our age, we are both equipped to prevent attacks and we are resilient in the face of those who would try to do us harm," Obama said. "And that's something we can all be thankful for."
Searching for suspects
In recent days, security forces have arrested dozens of suspects in Belgium and neighboring France. Belgium's prime minister, Charles Michel, said the extra security measures will remain in place at least until Monday.
The search for Salah Abdeslam -- believed to be among the Paris assailants -- and fears of an attack led Belgian authorities to impose the sweeping security measures. The steps were particularly tight in Brussels, home to the headquarters of NATO and many European Union offices.
Investigations of the Paris carnage quickly opened strands leading to Belgium.
Abdelhamid Abaaoud, the suspected mastermind of the attacks, was from the Brussels neighborhood of Molenbeek and is believed to have spent time in Syria. Abdeslam, a 26-year-old French citizen who is on the run, lived there with his brother, who was among the seven attackers who died in the assault -- the deadliest rampage on French soil since World War II.
French officials have accused Belgian intelligence and security services of missing chances.
On Tuesday, the Belgian federal prosecutor's office said Abdeslam was "checked" by police the morning after the Paris attacks while riding in a car with two other people on a highway to Brussels. They were allowed to go on their way.
But Belgian police subsequently arrested Mohammed Amri, the owner of the car, and Hamza Attou, one of the passengers, on Nov. 15 on terrorism charges, the office said.
Another person arrested on the same charges was a 39-year-old Moroccan from Molenbeek, identified only as Lazez A., the prosecutor's office said, noting that two pistols and traces of blood were found in his vehicle.
Belgium's prosecutor's office on Tuesday identified an additional suspect in connection with the attacks as Ali O., a 31-year-old French citizen also living in Molenbeek, saying he later drove a vehicle for Abdeslam.
Meanwhile, an international arrest warrant has been issued for another man, Mohamed Abrini, 30, who was spotted two days before the Paris attacks in a vehicle with Abdeslam on the highway to Paris, prosecutors said.
They said Abrini was seen on video surveillance at a gas station in Ressons, France, driving a Renault Clio that was later used in the attacks. That car and two others used in the attacks had Belgian license plates.
Belgian authorities described Abrini as 5 feet 8 inches tall with an athletic build and said he is "armed and dangerous."
Authorities have yet to identify four other men suspected of taking part in the attacks.
Information for this article was contributed by Maria Cheng and staff members of The Associated Press and by Loveday Morris of The Washington Post.
A Section on 11/26/2015