ATHENS — Greek anarchists vandalized the Athens home of the United States ambassador with black paint on Wednesday, according to the police, in the latest protest against the authorities’ rejection of a convicted terrorist’s request for a furlough.

The vandals defaced Ambassador Geoffrey R. Pyatt’s home about 4 a.m. before fleeing on motorcycles, a police official said. Eight people were briefly detained for questioning before being released without charge because of a lack of evidence linking them to the vandalism.

It was the second attack this year on Mr. Pyatt’s residence: In January, the home was vandalized to protest the United States’ support for Greece’s deal to recognize Macedonia on the condition it changed its name to North Macedonia. Anarchists defaced the embassy in the same month, protesting “American imperialism.”

In a post on Twitter, Mr. Pyatt, who was nominated by President Barack Obama to the post in 2016, described the Wednesday attack as “childish vandalism,” adding that he would “continue to work with Greek authorities to punish the culprits according to the law.” He added, “Destruction of property is not peaceful protest.”