The order to extend the remand against the two suspects, aged 24 and 31, was issued by magistrate Ainul Bashiirah Dona Don Biyajid following the expiry of the current order.
On Sept 29, two seamen died while being held at the detention unit.
The two are 28-year-old Nik Muhammad Baihaqy Nik Mat and 26-year-old Muhammad Lailatuliman Mohd Sukri
The two suspects were also remanded for investigations into the assault on two other seamen at the detention unit.
On Oct 2, two Class 1 seamen, both aged 30, lodged a police report claiming that they were injured at the same detention unit. They are currently receiving treatment at the Armed Forces Hospital here.