Greek police have detonated a small bomb found at a British car dealership in a southern suburb of Athens.
Triple blasts in Athens in early May heightened security concerns
The controlled explosion was carried out at the Land Rover dealership after an employee noticed a "suspicious box", said Greek police.
Authorities are on high alert following the triple bomb blasts outside a police station in the city on 5 May.
A Greek extremist group said it had carried out those attacks, criticising security for August's Olympics Games.
On Wednesday, two anonymous calls were made to media organisations claiming there was an explosive device near the car dealership, police said.
The first call was received at about 0030 local time and the other at 1330. Extensive searches of the area produced nothing.
The area is within a kilometre (0.5 miles) of the second-largest Olympic sports complex, on the site of the city's old seaside airport.