Belgian police on Tuesday killed a gunman in a raid on a Brussels apartment linked to Islamist militants involved in November's Paris attacks, and two others were on the run, state broadcaster RTBF reported.
Belgium's federal prosecutor said earlier one or more suspects had barricaded themselves into an apartment after police had come under heavy weapon fire through a door when carrying out the raid.
Belgian media said four police officers were wounded.
Belgian daily DH said one suspect was shot dead after being spotted from a police helicopter in a nearby garden.
Phone calls made by Reuters seeking comment from police and prosecutors were not answered.
French Interior Minister Bernard Cazeneuve said French police took part in the raid in the Belgian capital. Streets around the house in a southern section of the city were sealed off by police, Reuters journalists at the scene said.
"This operation is connected to the Paris attacks," a spokesman for Belgium's federal prosecutor said.
Reuters journalists heard gunshots as police commandos crowded into the street where the raid unfolded.
Investigators believe much of the planning and preparation for the Nov. 13 bombing and shooting rampage in Paris that killed 130 people were carried out by young French and Belgian nationals, some of whom fought in Syria for Islamic State.
The area around Tuesday's raid, near a car factory and a major north-south railway linking Paris and Amsterdam, was sealed off, and a police helicopter buzzed overhead.
Police told residents to stay indoors and schools and kindergartens close to the scene of the shootings were in lockdown, residents said.
Belgian security forces have been actively hunting suspects and associates of the militants involved in the attacks in Paris. Some of the attackers came from Brussels.
One of the prime suspects, 26-year-old Brussels-based Frenchman Salah Abdeslam, is still on the run. He left Paris shortly after his brother blew himself up in the attacks. Belgian authorities are holding 10 people who have been arrested in the months since the attacks, mostly for helping Abdeslam.
RTBF quoted French police sources as saying Abdeslam had not been the target of Tuesday's raid.
Brussels, headquarters of the European Union as well as Western military alliance NATO, was locked down for days after the Paris attacks for fear of a major incident there. Brussels has maintained a high state of security alert since then, with military patrols a regular sight.
Soldiers were on streets in central Brussels on Tuesday as the operation continued.
Belgium, with a Muslim population of about 5 percent among its 11 million people, has the highest rate in Europe of citizens joining Islamist militants in Syria. (Additional reporting by Miranda Alexander-Webber; Editing by Mark Heinrich)