A 21-year-old man set himself on fire in a Melbourne bank Friday, causing an explosion that left himself and five others in a critical condition, police said. According to dpa, the man has been placed under police guard in a local hospital. Twenty-seven people in total were injured in the fire and the explosion that took place Friday morning at the Commonwealth Bank in Springvale, south-west of Melbourne city. "He had some sort of accelerant with him in a container. Somehow that accelerant was lit inside the bank. He set himself alight with that fire," police inspector Jacqui Poida told reporters at the scene. She said it was too early to say if the incident was terror-related. The arson squad was investigating, she said. Another police officer, Paul Carrigg, said there was "evidence of an explosion," but did not say what caused it.