Twenty police vans were used in the raid in Jeumont on the French-Belgian border where a house was searched.
Earlier, French police released a photo of a fugitive who is on the run and described as too dangerous for anyone outside law enforcement to engage.
The man, identified as Salah Abdeslam, a 26-year-old born in Brussels, is one of three brothers believed to be involved in the killings in central Paris. He allegedly rented a black Volkswagen Polo used by a group of hostage takers who left at least 89 people dead inside the Bataclan concert hall, one official said.
Abdeslam was questioned by police and released hours after the Paris attacks, French officials told The Associated Press.
He was one of three people in a car stopped by police Saturday morning, after authorities had already identified Abdeslam as the renter of the Volkswagen Polo abandoned at the scene of the attack. Police released him after checking his ID.
It is not clear why the local police did not take him into custody.
One of Abdeslam's brothers has since been arrested in Belgium, and another brother detonated a suicide vest in the attack, authorities said.
Security officials indicated that there was an ongoing search operation in Brussels, the Belgian capital, for Abdeslam and other suspects.
Belgian officials said they had arrested seven people in Brussels after two Belgian-registered cars were discovered in Paris, both suspected of being used by attackers.
"I do not want any preachers of hatred on Belgian soil! There is no place for them in Belgium," Belgian Prime Minister Charles Michel said on Twitter.
French authorities also announced Sunday that the number of dead from Friday's coordinated assaults rose to 129, after three additional people died in the hospital. About 350 others were injured.
As Paris on Sunday mourned the victims, including at a special Mass at Notre Dame Cathedral, the city remained on edge.
French law enforcement officials reported that false alarms set off panic in several Paris neighborhoods, including Place de la Republique. One of the officials said a crowd in the plaza apparently panicked after hearing firecrackers. A French security official said someone had reached out to police in the plaza out of fear, and when officers arrived with weapons drawn, the crowd fled.
French authorities meanwhile said they have identified two more of of Friday's suicide attackers — one who blew himself up at the national stadium and another who attacked a restaurant in central Paris.
A judicial source speaking on condition of anonymity because she wasn't authorized to speak publicly said the 20-year-old Frenchman police identified as one of the three suicide bombers to strike at the Stade de France stadium was Bilal Hadfi.
A 31-year-old identified by police as the suicide bomber who detonated his explosive vest on Boulevard Voltaire in Paris was named as Brahim Abdeslam, the source said. Abdeslam is the older brother of 26-year-old Saleh Abdeslam, 26, who is currently the subject of an international manhunt.
A third man, who died in the assault on the Bataclan, was identified earlier as Ismael Mostefai, 29, a Paris native. His detached finger was found overnight at the Bataclan, the scene of the bloodiest attack. French media described him as a French-born man of Algerian descent. Paris prosecutor François Molins said Mostefai had a security file for radicalization, adding that he had a criminal record but had not spent time in jail.
All seven assailants were wearing vests packed with explosives and died during the rampage.
Since Friday, Belgium has detained seven people suspected to be linked to the Paris attacks.
Culture Minister Fleur Pellerin said all museums in Paris and nearby towns will reopen on Monday, two days after they were closed due to heightened security following the Friday rampage.