SYDNEY - Five Australians with H1N1 influenza have been admitted to intensive care units in the southern state of Victoria, with Australia now recording more than 1,200 cases of the illness but no deaths.

"They are in ICU (Intensive Care Units) and are pretty ill," a Victorian health spokesman told Reuters.

"Some may have underlying conditions that make their situation more at risk of contracting a more serious form of illness."

Four of the five patients were admitted to intensive care over recent days due to H1N1, but a fifth person with H1N1 had suffered a "trauma", said the spokesman.

The World Health Organization will hold an emergency meeting of experts on Thursday to discuss the spreading H1N1 flu outbreak, in a sign the U.N. agency may be poised to declare the first pandemic in more than 40 years.

There have been 27,737 cases reported in 74 countries to date, including 141 deaths, according to the WHO's latest tally.

Confirmed community spread in a second region beyond North America would trigger moving to phase 6 - signifying a full-blown pandemic - from the current phase 5 on the WHO's 6-level pandemic alert scale.