Greek police say a bomb disposal squad has been sent to the Russian consulate in Athens after cameras showed a suspicious object believed to be a hand grenade being thrown over the perimeter fence overnight.

Police said Friday morning that the consulate's cameras showed two people on a motorbike throwing a small object over the fence, reportedly causing minor damage. Authorities cordoned off the area around the consulate, located in a suburb north of the city center.

Police said they were also examining whether a motorbike found partially burned in a central Athens neighbourhood was related to the incident.

Greece has a long history of small groups that periodically attack symbols of state authority, wealth or foreign diplomacy. They usually plant small explosive devices that do not cause injuries.