A man threw an incendiary device at the door to the Israeli embassy in Bucharest on Monday, authorities said, adding that investigations did not indicate a link to the Gaza war.
Romanian counterterrorism forces detained the 34-year-old man who "threatened to set himself on fire and attempted to cause damage with a Molotov cocktail," a spokesman for the country's intelligence services said.
Counterterrorism forces, on site to ensure security, extinguished the resulting fire, which caused no significant damage.
Media reported the man to be a Syrian national.
Romanian police spokesman Georgian Dragan told Digi24 television that according to investigations so far, the attack was not related to Israel's war in Gaza, but instead resulted from "a personal dissatisfaction that he had not obtained a visa".
Security was increased around Israeli embassies around the world following the unprecedented October 7 attack on Israel by Palestinian Islamist militant group Hamas.
Last month, gunfire was heard near Israel's embassy in Stockholm. In late January, the bomb squad destroyed a "live" device at the embassy there, in what authorities described as a potential "terrorist crime".
In March, Dutch police also arrested someone suspected of throwing a burning object at Israel's embassy in The Hague.
The Gaza war was sparked by Hamas's October attack on Israel, which resulted in the deaths of 1,189 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.
Israel's retaliatory offensive has killed at least 36,479 people in Gaza, mostly civilians, according to the Hamas-run territory's health ministry.