Munyaradzi Gwisai, Hopewell Gumbo, Antonater Choto, Wellcome Zimuto, Eddson Chakuma and Tatenda Mombeyarra, were on Monday found guilty of plotting an uprising against President Robert Mugabe.
The prosecution on Tuesday called for the maximum 10-year jail sentence to be imposed on the six.
The ICJ said it was particularly concerned that the government of Zimbabwe was using repressive legislation to instill fear and prevent the free enjoyment of human rights by its citizens.
“In a country purporting to be democratic, laws ought to be used to protect citizens and not to prosecute them for raising human rights issues which the state is obliged to uphold. All persons ought to be equal before the law and all offenders should be legally accountable,” said Martin Masiga, the deputy director of the ICJ African regional programme.
The ICJ urged the government to investigate allegations of tortured raised by the six activists during their trial.
On Tuesday a conglomeration of South African civic organisations operating under the banner of Democratic Left Front (DLF), called on President Robert Mugabe led government to acquit the six activists who await sentencing on Wednesday.