Forty-three prisoners have gone on hunger strike in a Malaysian detention centre in protest at being held without trial or charge.
They include the son of a Malaysian opposition leader and dozens of other alleged Islamic militants suspected of links to the Jemaah Islamiah network.
They are held at the discretion of the Prime Minister, Abdullah Badawi, acting as home minister.
The government has not commented on the hunger strike.
Relatives say that 16 prisoners held under Malaysia's controversial internal security laws began refusing food and water on Monday.
The hunger strikers were arrested over a period of months in 2001 and accused of belonging to an organisation police dubbed "the Malaysian Mujahideen".
They include Nik Adli Nik Aziz, son of the spiritual leader of Malaysia's main opposition group, the Islamist Party, Pas.
Last year their initial detention orders were extended by a further two years.
The 16 have been joined by a further 27 who are declining to eat. They are alleged to belong to a related group, Jemaah Islamiah, believed to have carried out a series of bombings in Indonesia.
All are protesting against their detention, which, under Malaysia's Internal Security Act, can be extended indefinitely without charges being brought.
Human rights protests are being stepped up as Malaysia prepares to go to the polls.
It is expected that parliament will be dissolved and an election called within days. On Saturday a group of opposition politicians and human rights campaigners were targeted with water cannon and arrested for illegal assembly outside Malaysia's national police headquarters.
They had been trying to hand over a petition protesting against the alleged abuse of police powers. All 17 were later released.