The car bombing outside a California fertility clinic that killed one person and injured four others appears to have been driven by anti-natalist ideology, according to two senior law enforcement officials briefed on the incident.

Investigators are combing through the writings of a 25-year-old man believed responsible for an explosion that ripped through a Southern California fertility clinic over the weekend.

The bombing outside an American Reproductive Centers clinic in Palm Springs, California, shows how difficult the diffuse movement is to combat, say experts.