Sydney- Australia today says a man who killed himself and several other people in a suicide attack in Iraq last week was an 18-year-old from Melbourne. The attack took place in a market near a Baghdad mosque on Thursday. The man detonated explosives in a suicide vest, killing at least three other people and injuring dozens more. The Islamic State (ISIS) militant group, in an affiliated Twitter feed, said it was behind the attack and named the man as Abu Bakr al-Australi. Australia's Attorney-General George Brandis, in a statement, said the news was a "disturbing development". "The government deplores the violent actions being undertaken by ISIL (ISIS) and other extremist groups in Iraq and Syria, and is deeply concerned about the involvement of Australians in these activities." The involvement of Australians posed "a significant domestic security threat to Australia when those involved return home and seek to pursue violence here." The man was the second Australian suicide bomber in the Iraq and Syria conflicts, the statement added. Late last week, Foreign Minister Julie Bishop said the government was working hard to stop young Australians becoming radicalized. "We're doing all we can to prevent people going overseas as foreign fighters," the Australian Broadcasting Corporation quoted her as saying.