Australian Prime Minister Tony Abbott on Tuesday warned of heightened "terrorist chatter" in the aftermath of the fatal Sydney cafe siege and said another attack was likely, as tearful mourners paid tribute to the victims. Iranian-born gunman Man Haron Monis, who had a history of extremism and violence, took 17 hostages in the city's financial heartland last week, unveiling an Islamic flag and demanding to talk to Abbott. He was killed as armed police stormed the eatery after 16 hours. Two hostages also died -- mother-of-three Katrina Dawson, 38, and 34-year-old Lindt cafe manager Tori Johnson -- while several were injured. "A briefing from the security agencies today indicated that there has been a heightened level of terrorist chatter in the aftermath of the Martin Place siege," Abbott said after a meeting of his National Security Committee.
