Crowd numbers were down but the Anzac spirit was as strong as ever at dawn services marking the 101st anniversary of the Gallipoli landings by Australian and New Zealand soldiers.

Tens of thousands of Australians and New Zealanders have attended dawn services to mark ANZAC Day.

In the Australian capital, Canberra, about 55,000 gathered at the National War Memorial to commemorate the 101st anniversary of the landings of Australian and New Zealand soldiers at Gallipoli.

PM Malcolm Turnbull and Opposition Leader Bill Shorten attended the national Anzac Day service in Canberra where crowds of about 55,000 gathered. Mr Turnbull paid tribute to those who served and died in the war. He said Australia and allies including Turkey were currently facing a “war fought both abroad and at home and in every dimension.

Commemorations were held across the world, in Iraq, Villers-Bretonneux in northern France, and Gallipoli.

Governor-General Sir Peter Cosgrove delivered a touching address to approximately 5,000 Australians in Villers-Bretonneux.

Memorial director Brendan Nelson said Anzac Day was not about war, but about love and friendship.

“102,700 Australians are named on the roll of honour. Like us each had only one life, one life to serve others and our nation. They chose us,” he said.

NSW Premier Mike Baird described the arrest as disturbing, but urged people to still commemorate the day. “My strong encouragement is if you are intending to go (to an Anzac service), go,” he told reporters after the Martin Place dawn service.

Anzac commemorations were held across the nation and the world as Australia and New Zealand paid tribute to those who have served and died in war.

At Melbourne's Shrine of Remembrance thousands of people walked up the stairs at the end of the service to lay poppies. - AAP

At Melbourne’s Shrine of Remembrance thousands of people walked up the stairs at the end of the service to lay poppies. – AAP

Anzac Day was first held on 25 April 1916, making this year the centenary of the commemoration. “The day was marked by a wide variety of ceremonies and services across Australia, a march through London, and a sports day in the Australian camp in Egypt,” according to the Australian government website.

“In London more than 2,000 Australian and New Zealand troops marched through the streets; a London newspaper headline dubbed them “the knights of Gallipoli”. Marches were held all over Australia; in Sydney convoys of cars carried soldiers wounded on Gallipoli and their nurses.”

The day was later dedicated to all the Australians and New Zealanders who fought during the First World War and became a public holiday in the 1920s. In 1927, all Australian states held memorial services, vigils and services to remember those who died in WWI.

After the Second World War, Anzac Day also became a day to honour those who served overseas. Almost a million Australian men and women and around 140,000 New Zealanders served in the war.

Today, Anzac Day is a day of national remembrance which is also observed in the UK. Services are set to take place in London, including a wreath-laying ceremony and parade at The Cenotaph and a service at Westminster Abbey.

Members of the Albert Battery fire a gun salute during the Currumbin RSL dawn service in Gold Coast, AustraliaChris Hyde/ Getty Images

Members of the Albert Battery fire a gun salute during the Currumbin RSL dawn service in Gold Coast, AustraliaChris Hyde/ Getty Images