Greek police say that a number of shots have been fired at the German ambassador's residence in Athens. No casualties were reported in the attack.
Police said shots were fired from a Kalashnikov assault rifle at the German ambassador's residence in the Athens district of Chalandri in the early hours of Monday morning.
A police spokesman said no one was injured in the attack, in which reportedly around 60 shots were fired. Four of the bullets were said to have lodged in the garden gate.
The residence's police guard did not use his weapon for fear of harming neighboring residents, press reports said.
Police said six people were briefly detained for questioning, but were released without charge.
Both Greek Prime Minister Antonis Samaras and the Minister of Public Order, Nikos Dendias, have spoken with German ambassador Wolfgang Dold by telephone following the incident.
Samaras also telephoned with German Chancellor Angela Merkel.
Greek government 'outraged'
A foreign ministry statement has been released, condemning the attack.
"The Greek government expresses its outrage and outright condemnation of today's cowardly terrorist action, which had the only apparent objective of (damaging) Greece's image abroad," the statement said.
No one has so far claimed responsibility for the attack, but many Greeks blame Germany for the economic hardship caused by austerity measures imposed to meet conditions for international loans to combat the country's debt crisis.
German Foreign Minister Frank-Walter Steinmeier has voiced concern at the incident, but said it would not hurt Germany's relationship with Greece.
"There is nothing at all that can justify an attack like this on a representative of our country," he said, adding that the perpetrators would not manage to "destroy the good relations between Germany and Greece and between Germans and Greeks."
In a statement, Dold thanked police for a "swift response," and also gave assurances that the incident would not affect German-Greek ties.
"To those responsible for this action, I state it will not affect the close and friendly relations between our two countries, and it will not reverse the country's economic recovery," he said.
Diplomatic facilities, banks and foreign companies are often targets for attacks in Greece, with police mostly blaming them on left-wing extremists or anarchists. In the main, no casualties are caused.
In 1999, the German ambassador's residence was the target of a terrorist assault in which an anti-tank weapon was used. The underground Marxist group Revolutionary Organization 17 November claimed responsibility for that attack, in which no one was hurt.
tj/msh (dpa, AFP, AP)