A church-owned building in Jerusalem was torched overnight, the Israel Police said in a statement Thursday morning.
Arsonists set fire to an annex of a Greek Orthodox Seminary just outside the walls of Jerusalem's Old City, and scrawled "graffiti insulting Jesus" on the building.
Police spokeswoman Luba Samri called the incident a "nationalist" attack, with Jewish extremists believed to be the culprits.
There were no casualties and the fire was put out before causing any significant damage, she added.
On Tuesday, a Palestinian Arab mosque was set alight in a village near Bethlehem, with anti-Arab slogans in Hebrew sprayed on a nearby wall, Palestinian witnesses said.
Both fires are believed to "price tag" attacks - a euphemism for nationalistically motivated hate crimes by Jewish extremists which generally target Arabs, usually in revenge for terrorist attacks or demolitions of Jewish homes in Judea and Samaria.
Jerusalem Mayor Nir Barkat vigorously condemned the arson attack on the Greek Orthodox Seminary, saying, "There is no room for such deplorable activity in Jerusalem, we must eradicate this behavior and bring those responsible to justice."
Barkat also spoke with the Jerusalem Chief of Police and asked him to hurry the investigation. "We must quickly restore the peace and coexistence in Jerusalem," Barkat stressed.
AFP contributed to this report.