A man strangled an ibis and used it to threaten groups of people in Brisbane's CBD this morning.

Police said the man captured and killed the bird about 5:30am on George Street.

He then approached members of the public as they walked past and threatened them with the dead animal, they said.

Police attended and spoke to a man at the scene, but are now appealing for anyone who witnessed the incident or may have footage to contact them.

District duty officer senior sergeant Neville Mills said police took animal cruelty cases extremely seriously.

"Attacks of this nature will not be tolerated and those responsible will be dealt with to the full extent of the law," he said.