SYDNEY, Australia (AP) _ A man tried to extort $60 million from five countries by threatening to place bombs on planes and in public places during the Sydney Olympics, according to Australian police.

Mehmet Akin Kayirici, 35, of Sydney, was arrested Tuesday on extortion charges after a more than two-month investigation conducted with the help of the consulates involved, police said.

Peter Ryan, police commissioner for New South Wales state, said Kayirici's arrest showed security measures in place for the Olympics in September are ``robust.''

Kayirici appeared in court Tuesday after he was charged with nine counts of demanding money with menace and three counts of threatening to destroy aircraft.

Kayirici did not enter a plea and was ordered to remain in custody until a Friday hearing.

He is accused of making the threats in letters and telephone calls since December to the consulates of the United States, Britain, Israel, Russia and Turkey.

Police documents handed to the court say he demanded payments from the consulates or else he would destroy planes during the Olympics.

He also threatened to place bombs in public places during the Games and during last weekend's Gay and Lesbian Mardi Gras parade, police said.

Detective Superintendent Nick Kaldos said the threats were made first in letters, then in telephone calls.

``The letters contained demands of up to $60 million and listed potential targets both overseas and in Sydney,'' a police statement said.

Ryan said police took the threats seriously, although investigators did not find any connection between Kayirici and organized terrorist groups. He did not appear to have a way to carry out his threats.

A spokeswoman for the U.S. Consulate in Sydney said that U.S. authorities worked with Australian authorities on the case.