Belgian police killed two suspected terrorists and arrested a third in a shootout in the eastern town of Verviers, preventing a possible "major" attack, authorities said.

The raid, part of several anti-terror operations yesterday by the police, came after suspected Islamist gunmen last week killed 17 people in three days of attacks in and around Paris, including nine journalists at satirical magazine Charlie Hebdo.

The group in Verviers appeared to have no link with the shootings in France, according to the federal prosecutors’ office in Brussels. The suspects, some of whom police believed had recently returned from Syria, opened fire with automatic weapons as officers moved in, Eric Van Der Sypt, a spokesman for the prosecutors, said at a press conference late Thursday in Brussels. All of the suspects had Belgian citizenship.

"They were planning to commit serious terrorist attacks, and to do so imminently," he said. "They immediately opened fire. They didn’t even know who was at the door."

Police forces were the group’s intended target, Van Der Sypt said. The government raised the threat level for police across the country to three, the second-highest level, he said. No police or bystanders were injured in the operation Thursday.

Security forces across Europe have been on alert after the killings in France, the worst such attacks in that nation in more than 50 years. The French government said it will maintain the highest security alert for 15 days while it continues to investigate the terrorist attacks.

The Belgian anti-terror raids also took place in Brussels, where most European Union buildings are located. EU institutions were unaffected by the developments, European Commission spokesman Margaritis Schinas said.

Police searched a total of 10 locations in the town of Verviers and around Brussels. The probe leading to the raids began before the attacks in France and investigators found no links with the Paris shootings, Van Der Sypt said. A French official, speaking on condition of anonymity, said the incident in Belgium is probably not related to last week’s assaults.

Belgian Prime Minister Charles Michel, Interior Minister Jan Jambon and Justice Minister Koen Geens met late Thursday with the nation’s security services, the Belga newswire reported. Authorities learned of the planned attack through intercepted phone conversations, according to Le Soir newspaper. Van Der Sypt declined to comment on this.

The prosecutors plan to hold another briefing Friday at 11 a.m. in Brussels.