An arsonist torched the exterior of a California mosque early Sunday, leaving behind a note that referenced a white supremacist’s fatal mass-shooting of 50 people inside two Islamic houses of worship in New Zealand, according to a report.

The unapprehended firebug started a blaze around 3 a.m. alongside Dar-ul-Arqam in Escondido, a city about 30 miles north of San Diego, reported local NBC affiliate Channel 7.

Someone was inside the mosque at the time and was able to extinguish the flames before significant damage was done or anyone was injured, the outlet reported.

Responding cops found a note outside the mosque referencing the slaughter of 50 Muslim worshippers in Christchurch, New Zealand earlier this month, the report said, though the exact contents of the missive were not immediately divulged.

Brenton Tarrant, a 28-year-old former personal trainer from Australia, released online a rambling, hate-filled manifesto shortly before shooting up two mosques on March 15.

The attacks, which left 50 defenseless worshippers dead, were also live-streamed by Tarrant, creating an online record of the carnage that social media sites have struggled to scrub.

Tarrant was arrested and flashed a ‘White Power’ hand signal during a court appearance.