ASIO boss appalled by MH17 attack

One of Australia's top spies says he's shocked by the deadly attack on a Malaysia Airlines plane in Ukraine.

"I'm just appalled," ASIO director-general David Irvine told Sky News on Friday.

"I'm very anxious like everyone else to find out exactly what happened. We don't know what happened yet."

Asked whether Russia or its proxies were behind the attack, Mr Irvine said: "I have no idea at this stage."

The first task is to identify exactly how many Australians were on board and who they were, he said.