Italian Prime Minister Giorgia Meloni said the attack was likely carried out by "anarchists".
Greek police have launched an investigation after a suspected arson attack on two cars near the Italian embassy.
A homemade explosive device destroyed one of the vehicles early on December 2, while a second device failed to detonate. No injuries were reported.
The cars were located near the home of Susanna Schlein, the Italian deputy ambassador, on the outskirts of Athens. The Greek foreign ministry has “strongly condemned” the incident.
"Such reprehensible actions will in no way disturb the excellent relations and the long-standing bonds of friendship between Greece and its partner and ally, Italy," a statement read.
A Greek anarchist group -- known as Nucleus to avenge Carlo Giuliani" -- has claimed responsibility for the attack.
They stated that their actions were in support of a jailed Italian anarchist, Alfredo Cospito, who has been on hunger strike since October.
Italian Prime Minister Giorgia Meloni had earlier stated that the attack was likely carried out by people of “anarchist origin”.
Meloni expressed her "sympathy" and "deep concern" to Schlein and said he was " following the matter with the utmost attention."
Italian foreign minister Antonio Tajani was due to travel to Greece on Friday for a meeting with the European People's Party (EPP).
Arson attacks by anarchists and far-left groups are common in Greece and often target banks and vehicles belonging to foreign embassies.