Turkish authorities have arrested a suspected Islamic State member they believe was planning to attack a World War I commemoration at Gallipoli attended by hundreds of Australians and New Zealanders.

The suspect, a 26-year-old Syrian identified as Abdulkerim Hilef, was detained in Tekirdag, a northwestern province close to the Gallipoli peninsula, a Tekirdag police spokesman said.

9News understands the planned attack was "retribution for the Christchurch terror attack".

Turkish authorities have arrested a 26-year-old Syrian identified as Abdulkerim H. (Supplied)

But Prime Minister Scott Morrison today played down the arrest.

"This is more of a routine thing that we've seen happen with Turkish authorities and we could not say at all that there is any link between that arrest and any planned event at Gallipoli," Mr Morrison told reporters in Townsville.

"I would caution overstating any link between those two events."

Mr Morrison said the government had received reports suggesting any link between the arrest and the service was inconclusive.

The prime minister said normal security arrangements were in place and the services would go ahead as normal.

Prime Minister Scott Morrison greets veterans and current serving members of the Australian Defence Force at The Australian Hotel after the Anzac Day march in Townsville. (AAP)

Opposition Leader Bill Shorten, who is seeking security briefings on the arrest, said the situation should not deter Australians from attending Anzac Day services overseas.

"Just because there are terrorists in the world, we can't let them win by discouraging us from travelling," he told reporters in Darwin.

"Anzac Day is a sacred day. We can't afford to let these extremists discourage us."

He said the "marvellous" tradition of Australians, particularly young people, travelling to former World War I battlefields abroad should be maintained.

Labor leader Bill Shorten (third from left) lays a wreath during the Anzac Day dawn service in Darwin. (AAP)

Veterans' Affairs Minister Darren Chester said Australia was maintaining its travel advice urging people to exercise a high level of caution in Turkey.

"We take the security provisions obviously very seriously and we work closely with the local Turkish authorities," he told ABC Radio National.

Turkish nationals were banned from attending the dawn service at Gallipoli due to heightened security fears.

That directive came a month after Turkish President Recept Tayyip Erdogan’s controversial comments in which he said Australians with anti-Muslim views would be sent home in coffins like their grandfathers.

"Your grandparents came, some of them returned in coffins," the leader said.

"If you come as well like your grandfathers, be sure that you will be gone like your grandfathers."

Every year, Australians and New Zealanders travel to Turkey for memorial services on April 25. (AAP)

Mr Chester said it was "not unprecedented that Turkish nationals, local citizens are discouraged from attending the service".

Earlier, Australian War Memorial director Brendan Nelson praised Turkish authorities for going to extraordinary lengths to secure Anzac services at Gallipoli as he responded to reports of the arrest.

"It's a reflection of the fact that we do have some people who have heinous motives," he told reporters in Canberra.

"Unfortunately we live in a world where there are people - wherever they live, whatever their background, whatever their beliefs - who are fundamentalists intent on disrupting what we do.

"The most important thing we can do is go about living our lives."

People watch the Dawn Service at Gallipoli. (AAP)

Every year, Australians and New Zealanders travel to Turkey for memorial services on April 25.