BRUSSELS/PARIS (Reuters) - Belgian prosecutors said on Wednesday they had charged two Belgian nationals with terrorist activity after police found weapons and detonators during house searches overnight in the capital Brussels.

Police identified the two as Akim S, aged 40, and Khalid S, aged 37. They released two other people who had been briefly detained after the raids.

“They were charged with participating in activities of a terrorist group,” prosecutors said of the two detained.

In the same operation, which was conducted in cooperation with French police, a fifth person was detained across the border in northern France.

Police had searched four houses and two garages overnight in the Anderlecht district of Brussels. In one garage they found three Kalashnikovs, ammunition, other firearms and four detonators, the prosecutors said.

Police also found a blue police beacon, a security agency uniform, two police uniforms and a civil protection service uniform, suggesting that the group may have been planning an attack disguised as security forces.

Earlier Belgian state broadcasters said those arrested had links to a group called the Kamikaze Riders, a motor bike group based in the city whose members are mostly of North African origin and previously linked to jihadist groups.

They had plans to carry out an attack, Flemish-language broadcaster VRT said, citing sources, adding those plans were still at a very early stage and no specific target had yet been chosen.

There was no official confirmation of links to the Kamikaze Riders.

The prosecutors said Wednesday’s arrests were separate from investigations into Islamist attacks in Paris in November 2015, which killed 130 people, and in Brussels four months later in which 32 people were killed.

La Voix du Nord newspaper said the arrest in France had followed a raid by counter-terrorist police in the early hours of Wednesday in a suburb of the northern city of Lille.

The suspect fled the house but was detained in an adjacent street, dressed only in a T-shirt and shorts.