Sydney: The Australian police arrested a Sydney man on Monday as part of operations to disrupt the flow of money and fighters to conflict zones such as those in Iraq and Syria, where dozens of Australians are said to have joined Islamist militant groups.
The arrest of the 25-year-old man was part of investigations into the planning of an attack on Australian soil and the facilitation of travel of Australian citizens to Syria to engage in armed combat", the Australian Federal Police said in a statement.
The arrest happened several hours before streets in central Sydney were sealed off by police, with Australian television reporting that hostages were being held by gunmen in a cafe in the central business district.
There was no indication by authorities that the two incidents were in any way linked.
Australia is on high alert for attacks by radicalised Muslims or by home-grown militants returning from fighting in the Middle East, having raised its threat level to high and undertaken a series of high-profile raids in major cities.
Prime Minister Tony Abbott has said that at least 70 Australians were fighting in Iraq and Syria backed by about 100 Australia-based "facilitators".