Andrei Dmitriev, 41, an activist who leads an anti-Lukashenko social movement was detained in the capital Minsk on Wednesday, according to a message posted on his Facebook page.
Byalyatski, who shared the Nobel Peace Prize with Russian rights group Memorial and Ukraine's Center for Civil Liberties in October, was arrested in 2021 along with two co-workers.
The Iskander-M's two guided missiles have a range of up to 500 km (300 miles) and can carry conventional or nuclear warheads.
Russian President Vladimir Putin visited Belarus on Monday, raising fears in Kyiv of increased coordination between the two allies amid the invasion of Ukraine.
The Ukrainian Air Force said its air defenses shot down 30 drones, the third Russian air attack on the Ukrainian capital in six days.
72% of immigrants have not yet started studying Hebrew in an intensive program, also called an ulpan, while 30% gave up ulpan studies because they could not afford it.
Byalyatski's wife accepted the Nobel Peace Prize in his name and in the name of all "prisoners of conscience in Belarus."
Belarus has said it will not enter the war in Ukraine, but President Alexander Lukashenko has in the past ordered troops to deploy with Russian forces near the Ukrainian border.
Belarus is also reportedly seeking Iran's assistance with transitioning to a closed ammunition production cycle.
As Ukraine entered the strategic city of Kherson, an adviser to President Zelensky says that Ukraine intends to build a reinforced concrete wall and other fortifications on its border with Belarus.