An injured hostage is carried to an ambulance after shots were fired during a cafe siege at Martin Place in the central business district of Sydney, Australia, Dec. 16, 2014.

An injured hostage is wheeled to an ambulance after shots were fired during a cafe siege at Martin Place in the central business district of Sydney, Australia, Dec. 16, 2014.

Hostages run towards armed tactical response police as they run to freedom from a cafe under siege at Martin Place in the central business district of Sydney, Australia, Dec. 16, 2014.

Hostages emerge from a cafe under siege at Martin Place in the central business district of Sydney, Australia, Dec. 15, 2014.

A female hostage stands by the front entrance of the cafe as she turns the lights off in the Sydney central business district, Dec. 15, 2014.

Two hostages, left, run for cover behind a policeman, right, during a hostage siege in the central business district of Sydney on Dec. 15, 2014.

Two hostages run to safety outside the Lindt Cafe, Martin Place on December 15, 2014 in Sydney, Australia.

An armed tactical response police officer grabs a hostage as she flees from a cafe under siege at Martin Place in the central business district of Sydney, Australia, Dec. 15, 2014.

A hostage runs to armed tactical response police officers for safety after she escaped from a cafe under siege at Martin Place in the central business district of Sydney, Australia, Dec. 15, 2014.

Onlookers gather in Martin Place in the central business district of Sydney on Dec. 15, 2014. A gunman was holding hostages inside a Sydney cafe.

Armed police patrol on Dec. 15, 2014 in Sydney, Australia.

Armed police evacuates office staff next to a cafe in the central business district of Sydney on Dec. 15, 2014.

This image taken from video show people holding up what appeared to be a black flag with white Arabic writing on it, inside a cafe in Sydney, Australia, Dec. 15, 2014.

This image taken from video shows people holding up hands inside a cafe in Sydney, Australia, Dec. 15, 2014.

This image taken from video shows people against shop windows holding up hands inside a cafe in Sydney, Australia, Dec. 15, 2014.

Police evacuate people from an office building close to a cafe under siege at Martin Place in the central business district of Sydney, Australia, Dec. 15, 2014.

Armed police patrol on December 15, 2014 in Sydney, Australia.

Construction workers gather in front of the Sydney Opera House after being evacuated on Dec. 15, 2014 in Sydney, Australia.

An armed policeman is seen outside a cafe in the central business district of Sydney on Dec. 15, 2014.

Police stand at the ready close to a cafe under siege in Martin Place in the central business district of Sydney, Australia, Dec. 15, 2014.

Armed police are seen outside a cafe in the central business district of Sydney on Dec. 15, 2014.

A sniper sets up on Philip Street at Martin Place on Dec. 15, 2014 in Sydney, Australia.

Armed police patrol the vicinity at Lindt Cafe, Martin Place on Dec. 15, 2014 in Sydney, Australia.

Police officers chat on the scene of the siege at Lindt Cafe in Martin Place on Dec. 15, 2014 in Sydney, Australia.

Girls rush through Philip Street past armed police at a cafe on Dec. 15, 2014 in Sydney, Australia.

Police officers chat on the scene of the siege at Lindt Cafe in Martin Place on Dec. 15, 2014 in Sydney, Australia.

Armed police are seen outside a cafe in the central business district of Sydney on Dec. 15, 2014.