5 soldiers killed in Afghanistan

Five Australian troops were killed in two separate incidents in Afghanistan in what Prime Minister Julia Gillard on Thursday described as the nation's deadliest day in combat since the Vietnam War.

The deaths, which included three killings in an "insider attack" by an Afghan solider, brought to 38 the number of Australian lives lost in the conflict.

"This is a very big toll ... this is our single worst day in Afghanistan," said Gillard, who cut short a trip to the Pacific Islands Forum to return home and deal with the fallout.