Australian Prime Minister Tony Abbott says there has been a "heightened level of terror chatter" since the siege at a Sydney cafe last week.
Mr Abbott said the National Security Committee had met to discuss the development on Tuesday.
However, the terrorist threat level would remain at "high" and not be raised to "extreme", he added.
Earlier, memorial services were held for the two hostages killed by a gunman in the siege.
(Australia PM Abbott warns of 'heightened terror chatter.' BBC News. December 23, 2014.)
"heightened level of terror chatter"という表現における"chatter"は、いわゆるインテリジェンス活動に関連する専門用語で、諜報活動により傍受された通信のことを意味するようです。
The State Department issued a "worldwide caution" Thursday, warning that the newly released tape of Osama Bin Laden and a recent increase in intelligence "chatter" might indicate an imminent terrorist attack. What kind of intel counts as chatter?
When intelligence agencies monitor chatter, they examine not the content of communications intercepts, but the volume. Intelligence agencies won't define the term publicly because, they say, any disclosure might help the enemy deconstruct their methods and devise a defense. But those with knowledge of the agencies' tactics say that operatives pay attention to fluctuations in the number of messages sent and received over networks used by known and suspected terrorists.
(David Joachim. What Is Intelligence Chatter, Anyway? Slate.com. September 12, 2003.)
messages sent and received over networks used by known and suspected terrorists