The Singapore branch was under the command of a Malaysia-based leadership structure called a regional shura (consultative council), within the larger network of JI organisation in Southeast Asia.
According to investigations, the cell had conducted survey for other targets as early as 1997, when the cell was planning to target Yishun MRT station, where American troops and their families used to take shuttle rides to the US Navy site at Sembawang for recreation activities at a sports complex coincidentally known as the "Terror Club", named after the Royal Navy shore accommodation establishment HMS Terror.
[2] In early October 2001, Fathur Rahman al-Ghozi, also known as Mike, and Mohammed Jabarah, also known as Sammy, flew to Singapore and directed the sleeper cell to conduct "final reconnaissance" and video recordings of potential targets.
Among the targets were U.S. and Israeli Embassies, British and Australian High Commissions, the Singapore American School, and commercial buildings housing US firms.
[4] The other man, Sammy, was later identified as Mohd Mansour Jabarah, a Canadian national of Arab descent, who was in US custody (as of 2003) and sentenced to life in prison in 2008.
In an interview on PBS, Lee Kuan Yew pointed out that each bomb would be twice the size of the one detonated by Timothy McVeigh at the Alfred P. Murrah building in Oklahoma City.
After the 11 September 2001 attacks, an informant told the Internal Security Department about Muhammad Aslam Yar Ali Khan, who is a Singaporean citizen of Pakistani descent and had made claims of having ties with Al-Qaeda.
During the raids, the police seized documents of the attack plots and bomb making information, as well as photographs and surveillance video of the intended targets including the embassies.
The video showed a narrator in Singapore, Hashim bin Abas, describing how bombs could be hidden to attack United States interests.
[6] The JI group were also plotting to attack United States Navy personnel and their families who often traveled between the Yishun MRT station and Sembawang Wharf via shuttle buses.
The video also detailed how bombs could be planted in the sewers and drains near the Yishun MRT Station in order to cause massive casualties when targeting United States personnel.
[1] Investigators in Singapore had found similar tapes at the residence of Mohamed Khalim bin Jaffar, one of arrested JI members.