The childcare centre, located near a Jewish school and synagogue in the city's east, suffered extensive damage but there were no reports of injuries in the attack which occurred around 1 a.m. (1400 GMT, Monday), police said.
It was the second antisemitic attack on property in four days in Sydney, and comes amid a spate of similar crimes targeting the Jewish community in Australia's most-populous city.
New South Wales state Premier Chris Minns said the perpetrators would be caught and police had put more resources into investigating hate crimes, as public frustration grows over the lack of arrests following previous antisemitic attacks.
"The kind of people who would ... attack a fellow Australian whom they don't know because of their race or religion, it is completely disgusting and these bastards will be rounded up by the police," Minns said during a media briefing.
Australia has seen a rise in antisemitic and Islamophobic incidents since Israel retaliated against an attack by Hamas on Oct. 7, 2023, with an assault on Gaza that has left tens of thousands of people dead. At least half a dozen incidents were reported in the last two months in Sydney alone.
Prime Minister Anthony Albanese described the latest attack as "a vicious crime."
Albanese is facing a national election due by May and antisemitism is shaping as a key issue, with the opposition criticising him as "weak" for not doing enough to prevent hate crimes against Jews.
In response to the spate of attacks, the Australian federal police has launched a task force to investigate threats and violence against the Jewish community.
A 44-year-old man was charged last week, the first by the task force, for allegedly making death threats against members of a Jewish organisation.
