In a series of 22 raids carried out late Sunday evening, armed Belgian police officers arrested 16 individuals around Brussels and the surrounding area who are believed to be connected to last week’s terrorist attack in Paris. The key subject of Belgium’s national manhunt, however, Salah Abdeslam, remained at large.

Amid the raids, residents were told to stay inside and away from windows. Helicopters circled above as armored police vehicles roamed the streets.

Speaking at a news conference late Sunday night in Brussels, Thierry Werts, from the Belgian prosecutor’s office, and Eric van der Sypt, a federal magistrate, said the operation was ongoing as they continued to hunt for Abdeslam, the Guardian reported on its live blog. The officials noted that police did not find any weapons or explosives during the raids and that the 16 men who were arrested will appear before a judge on Monday.

The 26-year-old Abdeslam, who has been named by CNN as “France’s Most-Wanted Man,” is the suspected driver of the black Renault Clio that carried three suicide bombers to the soccer stadium in Paris.

Salah Abdelsam Salah Abdelsam is being hunted by Belgian police for his involvement in the Paris terror attacks. Photo: French police

The Sunday evening raids culminated a weekend of heightened security in Brussels, which will remain in lockdown into Monday. As the terror alert remains on its highest level, schools, universities and the subway system will be closed on Monday. "The threat remains serious and imminent in Brussels," Belgian Prime Minister Charles Michel said at a news conference earlier on Sunday.

He added, “We still fear attacks here like those that occurred in Paris, involving several individuals striking simultaneously in several places.”