Assessors have found hundreds of homes and boats have structural damage in the hardest- hit area in Australia's Queensland where Cyclone Yasi made landfall, the state Emergency Services Minister Neil Roberts said on Thursday.

Roberts said the storm surge had kept authorities out of low-lying areas to assess the damage on Thursday, but aerial crews had flown over the areas to take a look.

At the coastal town of Cardwell in north Queensland, about 60 properties have major structural damage, 100 have "medium level damage" and 50 have minor damage, he said.

At Mission Beach, the state's north coastal town, about 22 properties have major structural damage.

At Tully Heads, near Mission Beach, 21 properties have major damage, 19 have medium damage and 12 have minor damage.

In the Hinchinbrook area, about 180 km south of Cairns in north Queensland, 70 boats in a harbor have major damage to them.

"I do want to stress, however, that this is aerial surveillance and until we get people on the ground making assessments property by property, they are preliminary assessments," Roberts told reporters.

"But I think that does give an indication that there is quite significant structural damage to properties, particularly in the area where the cyclone crossed the coast."

Roberts said a second storm surge of half a meter above the highest tide level that had affected Cairns and Townsville on Queensland's north coast had passed.

However, there were still concerns about flash flooding from heavy rain in areas such as Ingham and Giru in the region.

There were still no reports of deaths or even major injuries from the cyclone, Roberts said.

Red Cross teams were moving into the coastal towns of Tully and Innisfail in north Queensland to establish more permanent evacuation centers for people who were made homeless by the cyclone, he said.