Updated

Australia and New Zealand are warning that extremists may be planning an attack on the commemoration of a World War I campaign that is being held in Turkey this month.

Australian Veterans Affairs Minister Dan Tehan on Thursday urged the more than 500 Australians and New Zealanders registered to travel to Gallipoli, Turkey, to mark ANZAC Day on April 25 to exercise a high degree of caution. But he offered no specifics about the alleged threat.

ANZAC Day commemorates the April 25, 1915, landings in Gallipoli. It was the first major military action fought by the Australian and New Zealand Army Corps during World War I.