A large bomb has exploded in central Athens, causing extensive damage to buildings but the UK Foreign Office said there are no reports of any injuries.
The blast happened in the early hours of this morning outside the Greek Business Federation offices and close to the parliament building and Syntagma Square.
Windows in nearby buildings were shattered, according to Greek authorities.
Police have sealed off the area near Syntagma Square and launched an investigation.
No group has so far said it caused the blast and the FCO has not altered its travel advice for British visitors to Greece.
A large group of football fans is expected to travel to Athens early next month when Arsenal play Olympiacos on December 9.
