Thirty Palestinian political prisoners being held in Israeli jails have begun an open-ended hunger strike to protest their administrative detention , a policy that means they are being held without charge or trial.Israeli authorities have been using the obscure legal procedure for more than half a century, basing it on secret evidence, to imprison people without charge or trial for an indefinite amount of time.Israel’s policy allows the detention of Palestinians for renewable intervals usually ranging between three and six months. Their imprisonment is based on undisclosed evidence that even a detainee’s lawyer is barred from viewing.Israel claims the policy is necessary for security reasons and allows the government to hold dangerous suspects without revealing intelligence information.Amnesty International has described Israel’s administrative detention policy as a cruel and unjust practice which helps maintain Israel’s system of apartheid against Palestinians.