Siege Gunman Had History of Mental Instability and Extremism: Tony Abbott

Sydney: Australian Prime Minister Tony Abbott said on Tuesday the gunman behind the Sydney cafe siege was well known to authorities and had a history of mental instability.

"The perpetrator was well known to both state and commonwealth authorities," Abbott told reporters in a brief press conference in Canberra. "He had a long history of violent crime, infatuation with extremism and mental instability."

"These events do demonstrate that even a country as free, as open, as generous and as safe as ours is vulnerable to acts of politically motivated violence," Abbott said.

A police source named the gunman as Man Haron Monis, an Iranian refugee and self-styled sheikh facing multiple charges of sexual assault as well as being an accessory to murder.