PM: 1 arrested in Australia over alleged bomb plot
Prime Minister Tony Abbott

At least one person has been arrested in Australia over an alleged bomb plot, Prime Minister Tony Abbott said Saturday, after saying that the country faced a "very serious terror threat".

"There have been some raids over the last 24 hours in Sydney and Melbourne. There's been at least one arrest. There is evidence of a bomb plot that was in a reasonably advanced state of preparation," Abbott told reporters.