The Department of Foreign Affairs and Trade says four of the Australians who remain in hospital are in intensive care.
They were being treated in Cairo's Dar El Fouad and Al Haram hospitals.
Surgeons in Egypt say they've successfully operated on an Australian woman who was among the most severely injured in the crash.
Six Australians died in Wednesday's crash on the road between Cairo and Alexandria.
Egypt’s official Mena news agency said 24 of the 27 people injured are Australians.
The Egyptian driver of the bus, Mahmud Mohammed Hafez, was also hurt.
The bus overturned in wet weather on a road about 8.45pm Tuesday evening local time (5.45am AEDT Wednesday) about 50 kilometres north of Egyptian capital Cairo.
It was one of two vehicles carrying a tour group of 80 Australia police, emergency service workers and their relatives from Alexandria to Cairo.
First passengers speak
Two of the Australian survivors have described the crash as the best and worst day of their lives.
Gary Waugh, sitting beside his wife Debbie who lies in a Cairo hospital bed in a neck brace, said the pair had been having a great holiday before the accident.
"You read about these things but you never actually think that you're going to be involved in it," he told the ABC from Cairo.
“And I think that myself and my wife were making comments today, just after it happened, that it was almost the best and worst day of our lives. In terms of - we'd had a great day and it turned into what it did."
Mr Waugh described the crash scene as chaotic with many people crying out in pain.
"A number of people came to our aid in a very short space of time - it was only a matter of minutes," he said.
"One side of the roof must have been shorn so that they pulled the roof off. There were about six or seven men who were yelling loudly and they pulled the roof off."
The Waughs lost somebody close to them who was traveling with them from Australia but Mr Waugh stopped short of identifying that person.
“It's not just being in the accident but being close to at least one of the people who was killed is not something that I'll ever get over," he told the ABC.
Five of those killed are from the south-eastern Australian state of Victoria.
Others on the tour were from Queensland and the Northern Territory.
Names released
Those killed in the accident include:
• Drew Ritchie, 14, of Wedderburn, Victoria
• Mark Ritchie, Drew's father, also of Wedderburn, Victoria, and a coordinator at Bendigo Senior Secondary College
• Senior Constable Kristy Olsen, of Moe Police, Victoria
• Sergeant George Panayiotis, who worked with the radio and electronics unit in Melbourne
• Melbourne plastic surgeon Dr Warwick Lorne Greville, 68, from Balwyn
• Luciano Prenner, 56, of Brisbane
Driver under police guard
The injured driver of the bus, Mahmud Mohammed Hafez, has been placed under police guard in hospital, as reports suggest he had taken evasive action, just before the accident happened.
Passenger Gary Waugh said the bus was not speeding at the time of the crash and there was no rain or fog but the road was wet.
"Because I had my eyes closed, and this is a bit about self-preservation, I didn't actually know the bus had rolled so I'd lost a sense of where I was," he said.
Australian ambassador Bob Bowker says the first significant rain of the winter is one likely cause of the accident.
"Conditions that evening were particularly poor and we would believe contributed to the tragic result, " he told ABC Australia.
Driver fatigue
Driver fatigue has also been suggested as a possible contributing factor.
Victoria Police Chief Commissioner Christine Nixon said the cause of the crash has not yet been established, but it appears the bus was overtaking a second busload of people on the tour when it overturned.
"The police are investigating in Egypt but it appears from a well-informed source that the buses were returning late from an outing which had started early in the morning," she said.
"Certainly from the contacts we have had it was horrendous, the accident," she said.
Ms Nixon said there have been suggestions that driver fatigue may have been a factor, as the tour had been on the road since five that morning.
Exchange tour
The Australians were part of a convoy of two buses returning from a visit to the El Alamein battlefield near Alexandria.
They were in Egypt as part of a cultural and professional exchange with Egyptian police.
The Australian Department of Foreign Affairs and Trade has set up a hotline number: 1800 002 214