2014 Sydney hostage crisis
After the siege began, a staged exclusion zone was established with thousands of people evacuated from nearby buildings, including from the floors above the café. The Sydney Opera House was evacuated after a suspicious package was found; however, reports were unconfirmed by police. The US Consulate General in Sydney, located in Martin Place, was also evacuated. Some Sydney schools were put in "white level lockout" due to the hostage situation, which meant that no school group was permitted to leave the school grounds.
Attack on Sydney Harbour
"I-29"s floatplane made a reconnaissance flight over Sydney on 23 May. A secret radar unit set up in Iron Cove detected the flight, but authorities dismissed its report as a glitch, as there were no Allied aircraft operating over Sydney. The aircraft was damaged or destroyed on landing, although its two crew survived. They reported the presence of several capital ships, including two battleships or large cruisers, five other large warships, several minor war vessels and patrol boats, and prolific merchant shipping. The report, which the Allied FRUMEL signals intelligence network partially intercepted, resulted in the Japanese Navy selecting Sydney as the target. The three midget-carrying submarines rendezvoused with "I-29" and "I-21" approximately north-east of Sydney Heads, with all five submarines in position by 29 May.