Rescue crews are searching for those trapped after a four-storey apartment block collapsed on Tuesday in the Petralona area of Athens, the fire brigade said.
Four people who were earlier reported trapped have been located and are safe, but the operation continues.
A team with rescue dogs are searching the rubble while other forces are on standby.
Footage on local media showed rescue workers walking amid the rubble.
It was not clear what caused the collapse of the building, which included seven apartments. Construction work was underway in an adjacent building, the fire brigade said
