Former parliamentarian Remzi Kartal and his assistant Zubeyr Aydar were detained in a wide-scale operation launched in Belgium against PKK organization.
Police also raided studios of ROJ TV, broadcast organ of the PKK, in Denderleeuw town near Brussels and detained four people.
Some 300 Belgian police raided 25 addresses across the country in an operation against PKK.
Residences in Brussels, Antwerp, Charleroi, Namur and Verviers were searched as well as the offices of Kurdish television broadcaster ROJ in the town of Denderleeuw.
Belgian prosecutors said they planned to release information later in the day.
Police also raided studios of ROJ TV, broadcast organ of the PKK, in Denderleeuw town near Brussels and detained four people.
Meanwhile, it was reported that PKK called its supporters to launch a protest in front of ROJ TV offices.
The PKK, which launched an armed attacks against the Turkish state in 1984 in southeastern Turkey, is branded a terrorist organisation by Ankara, the European Union and the United States.