The Saudi Arabian Football Federation has apologised after its national team did not properly observe a minute's silence for the victims of the London attacks before the start of a World Cup qualifier in Australia.

The Australia team lined up in the centre circle ahead of the match at Adelaide Oval late on Thursday but all bar one of the Saudi players, although silent, dispersed around the pitch and continued to jog and stretch.

Eight people were killed and 50 injured after three Islamist militants drove into pedestrians on London Bridge last Saturday, then attacked revellers nearby with knives. Two of the dead were Australian.

Football Federation Australia (FFA) said it had "sought agreement" from the Saudis and regional governing body, the Asian Football Confederation (AFC), to hold the minute's silence.

"Both the AFC and the Saudi team agreed that the minute of silence could be held," a spokesman said.

"The FFA was further advised by Saudi team officials that this tradition was not in keeping with Saudi culture and they would move to their side of the field and respect our custom whilst taking their own positions on the field."

The governing body of Saudi football later issued a statement saying it "deeply" regretted and "unreservedly" apologised for their players not "formally" observing the minute's silence.

"The players did not intend any disrespect to the memories of the victims or to cause upset to their families, friends or any individual affected by the atrocity," it added.

"The Saudi Arabian Football Federation condemns all acts of terrorism and extremism and extends its sincerest condolences to the families of all the victims and to the government and people of the United Kingdom."

The AFC said it had monitored the incident, as well as "various statements", but that any disciplinary action against the Saudis would have to come from world governing body FIFA, who have jurisdiction over all World Cup qualifiers.

The incident prompted a social media storm and comes at a time when Australians are still mourning victims of recent attacks.

In addition to the Australians who died in London, a deadly siege in Melbourne on Tuesday that Prime Minister Malcolm Turnbull called "an act of terrorism" claimed one victim, while an Australian schoolgirl was one of more than a dozen killed in a Baghdad car bomb blast last week.

Turnbull said on Friday that he had not seen video of the incident at the Adelaide Oval but thought everybody should condemn "terrorism".

"The whole world, the whole free world, is united in condemnation of that terrorist attack and terrorism generally," he told reporters in Tasmania.

"The heartbreaking, heartbreaking loss of young Australians in London, of course in Baghdad, and just this week in Melbourne to these murderous terrorists - everybody, everyone should be united in condemnation of the terrorists and love and sympathy and respect for the victims and their families."

Australia won the match 3-2 to move level on 16 points in Group B with the second-placed Saudis and leaders Japan, who have a game in hand, with two rounds to play.

The top two teams win a place at the World Cup finals in Russia next year.