Five people are now in custody in Belarus suspected of involvement in the deadly metro bomb blast that left 12 dead and 150 injured.
Police made three arrests on Wednesday, including the man whom they accuse of carrying out the attack on a crowded metro station in the capital Minsk.
Authorities say all five hail from Belarus and are under 30 years of age.
Police claim they have proof that one of the suspects was involved in making a bomb, which exploded in Minsk in 2008.
It is being reported that two of those detained, an electrician and a lathe operator, confessed to the attack, along with two other blasts in 2008 and 2005.
There are fears that President Alexander Lukashenko, an authoritarian leader who has ruled the country since 1994, could use the bombing as a further excuse to crackdown on political opponents.