Man 'seizes child hostage' at a court in Sydney

A man with a backpack which he says contains explosives is holding a child at a courthouse in a suburb of Sydney in Australia.

Video footage showed him shirtless and wearing a lawyer's wig, as he looked out of an office window.

New South Wales State Police Assistant Commissioner Denis Clifford told reporters that the man's claims of having a device were a matter of ''great concern'' to the police.