"Three people have been detained, they include persons belonging to an underground organization, as well as those having special skills in the use of explosive substances," said Igor Kuznetsov, the head of the Belarusian State Security Committee's Minsk Region department.
An explosion rocked Minsk July 3 during an open air concert as part of the country's Independence Day celebrations attended by President Alexander Lukashenko. Over 50 people were injured in the blast, caused by a homemade device.
Earlier the wife of one of the suspects in the criminal case said two Belarusian opposition activists had been detained as part of the investigation.
The Interior Ministry has declined to comment on the arrests saying they have the legal right to detain anyone suspected of being involved for a period of up to three days.
Authorities in the ex-Soviet state have come under severe international criticism for their clampdown on dissent. Hardline leader Lukashenko is currently barred, along with other senior officials, from entering the United States and the European Union over his suppression of democratic freedoms.
