Serious harm may have come to fighters: PM

Prime Minister Tony Abbott says serious harm may have come to Australian foreign fighters Khaled Sharrouf and Mohamed Elomar, but he can't confirm deaths.

Prime Minister Tony Abbott says he can't confirm whether two of Australia's most prominent foreign fighters are dead.

But serious harm may have come to the "evil terrorists" Khaled Sharrouf and Mohamed Elomar, he told reporters in Canberra on Tuesday.

The Sydney men are believed to have been killed in Iraq during drone strikes on Mosul.