A suspected jihadist group targeted in a major anti-terror raid on Thursday had been planning to kill policemen in the street and at police stations, Belgian prosecutors say.
The planned attacks were imminent, they said, adding that two suspects shot dead in Verviers during the raids were still being identified.
Thirteen suspects have been arrested, while two more were arrested in France, the BBC reports.
Guns, munitions and explosives, as well as police uniforms and a large amount of money, were seized during the overnight raids, prosecution spokesman Thierry Werts told reporters.
Belgian officials say more than 300 people have left Belgium to fight with Islamic militant groups in Syria and Iraq. The country is thought to have the highest number of foreign fighters per capita in Europe who have taken part in fighting in Syria.
The suspects shot dead on Thursday had returned from the country, police said. They had shot at police "for several minutes" before being killed, prosecutors added.
In other developments in Europe:
- French police said 12 suspects were being held over "possible logistical support" given to the gunmen behind the Paris attacks
- The Gare de l'Est train station in Paris was evacuated for an hour on Friday morning following a bomb threat
- German police arrested two men following raids on a group suspected of planning an attack in Syria