Australia's Test cricketers have been instructed to re-join their state squads for training as deliberations on the proposed tour of Bangladesh continue.

The 15 players lead by new skipper Steve Smith had been expected to fly out on Monday morning for Bangladesh, and have been on standby since while CA sent a security delegation to Dhaka to assess the risks.

A cancelled tour would cause a ripple effect throughout the Matador BBQs One-Day Cup, with the Test players return squeezing some out of state squads. Those players could then be moved into the new CA XI team.

The Australian squad had not assembled – players were due to fly from their home ports and meet in Dhaka. The NSW Blues Matador Cup squad will now be joined by the five Test players – Smith, Nathan Lyon, Peter Nevill, Stephen O'Keefe and Mitchell Starc.

Western Australia had four players in the Test squad including Adam Voges, Cameron Bancroft, Mitchell Marsh, Shaun Marsh.

Joe Burns and Usman Khawaja are back with Queensland; Glenn Maxwell, Peter Siddle with Victoria, and the uncapped Andrew Fekete rejoins Tasmania. James Faulkner had already been part of Tasmania's plans before he was called up to the Test squad as Pat Cummins' injury replacement.

South Australia is the only state to have their Matador One-Day Cup preparations unaffected.

Cricket Australia officials will continue their talks on the security situation in Bangladesh with further talks today with the Department of Foreign Affairs and Trade in Melbourne.

CA's security delegation arrived home from Dhaka late on Tuesday having received briefings and reassurances from the highest levels of Bangladeshi government and security organisations.

Head of Security Sean Carroll will discuss his findings from his Dhaka visit with DFAT and will report to CA's Board and the Australian Cricketers' Association player union.

Bangladesh Cricket Board president Nazmul Hasan said he remained optimistic the tour would proceed as planned, with the first Test due to start on October 9 in Chittagong.

"We have assured them the highest level of security and I don't think any other country has ever offered a team such a level of security. If they don't come despite all of that it will be disappointing," Hasan said.

"It will be hard to accept as well, since three teams toured here a few months ago. Even Indian Prime Minister Narendra Modi came here for a visit recently."

Visits by the cricket teams of South Africa, Pakistan and India have passed without incident this year but the situation changed with last Friday's warning from the Australian government of "reliable information" of militant action.

The governments of the United States, the United Kingdom and Canada have all followed suit in warning their citizens of possible militant attacks.

A large annual expat party in Dhaka organised for this weekend has been cancelled amid the security threat. The annual 'Glitter Party' organised by Australian and New Zealand expats had been held in the city for the past 26 years.

The situation was further clouded on Monday when an Italian aid worker was gunned down in Dhaka, with multiple international media agencies since reporting the Islamic State had claimed responsibility for the attack.

A DFAT spokesperson said it was aware of the Islamic State claim but it had not yet been verified.

"We are aware that the Islamic State of Iraq and the Levant (ISIL) has claimed responsibility for this attack," a spokesperson for DFAT said in a statement.

"If confirmed, this further highlights the credible and serious nature of the current threat."

The BCB president played down the link between the murder and the Australian cricket team's proposed visit.

"After the murder of the Italian citizen, the security team might have been a little concerned since these instances are very rare in Dhaka," Hasan told Bangladesh media.

"But you can't compare this incident to a scenario where a team will get full protection. I don't see any reason for them to be scared.

"The Australian team which left here will present the security details back home and we should know their response within two days' time," said Hasan. "They still haven't said no… we can only after take any steps after they respond."