A bomb went off at 01:29 on Saturday at the Labor Ministry on Stadiou street, damaging the front and windows of the building and nearby buildings.

The bomb had been placed in a backpack and hung on railings across from the ministry, in front of a bank branch which was shut down for renovations. Police specialists believe the bomb was placed there so the shock wave would be directed at the ministry.

Before the blast, two warning calls were placed by an unknown person to Efimerida ton Syntakton daily. In the first call, the unknown individual warned that a bomb had been placed outside the ministry and would be detonated in 40 minutes, but then called again to say it had been placed across from the ministry, at the bank branch.

He also said that the responsibility for the bomb was claimed by the "Revolutionary Class Self-Defense", a firt-time appearance of this organization.
Police said they were warned by the newspaper at 00:48 and they cordoned off the area, stopping traffic on

Stadiou street at the Pesmazoglou cross-street, while a bomb squad was called in.
Stadiou street remained shut all night, with traffic being restored shortly after 09:00 on Saturday. 

The bomb squad has collected material from the explosion, while the Counterterrorism Service has begun collecting material from nearby cameras.