SINGAPORE - Three of the 1,560 SingPass accounts compromised last month were fraudulently used to make six work pass applications. The Ministry of Manpower (MOM) and the Infocomm Development Authority confirmed this in a statement Friday evening.

The work passes have been cancelled. MOM said it has also put in place "additional measures to strengthen and further safeguard its work pass transactions", but it did not elaborate.

SingPass secures residents' access to some 340 e-government services, including those for filing income tax returns and checking CPF account balances.

Last month, the Infocomm Development Authority (IDA) said it would be "refining" the SingPass system by the third quarter of 2015 after it was revealed that the personal data of 1,560 residents here could have been tampered with.

The IDA is considering implementing two-factor authentication for e-government transactions, particularly for those involving sensitive data, and letting users set their own usernames instead of using their NRIC numbers.