NSW Police have launched a major investigation into an online threat at a newly opened mosque in Sydney's south-west.

Many in the Muslim community say it's left them feeling distressed, disturbed and heartbroken during the holy month of Ramadan.

Meanwhile, sweeping US tariffs on imports from Canada, China, and Mexico have now come into effect, triggering retaliatory measures and threatening to ignite a global trade war.

President Donald Trump believes the tariffs will spur investment in the United States.

But economists say it's American consumers and businesses who'll be hit the hardest. 

And millions of people in south-east Queensland and northern New South Wales are bracing for the arrival of Tropical Cyclone Alfred.

TC Alfred is expected to make landfall as a category two storm between Brisbane and the Sunshine Coast on Thursday or Friday, but heavy rain and strong winds are forecast for the wider warning zone.

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