Four members of a Jemaah Islamiah suicide bombing squad who were arrested last week planned to attack the US embassy and cut water supplies in neighbouring Singapore, officials said today.

An official said on condition of anonymity that the police had arrested three Malaysians and one Singaporean last week. Security forces are still searching for four other members of the team.

"These people are the ground force who are trained to carry out suicide operations against Western interest and other key facilities," the source told

"Bashir and Hambali are their leaders. That is why the duo are on our wanted list."

Muslim cleric Abu Bakar Bashir ( photo )has been accused of being the spiritual leader of the Jemaah Islamiah (JI) regional terror group while Riduan Isamudin, alias Hambali, has been named as the network's military chief.

Police in Indonesia have said that key JI operative Imam Samudra ( photo ) has admitted masterminding last month's Bali bomb which killed more than 190 people although some reports have said that senior members of the al-Qaeda network are also being sought in connection with the blast.