Rights group Amnesty International has welcomed the decision by Zimbabwe's Constitutional Court to outlaw a public order act that prohibits demonstration without authorisation from the police.

"For far too long, this repressive piece of legislation has been used to systematically harass, arbitrarily detain and torture people seen as opposition supporters or those trying to expose human rights violations. The fact it is no longer on the statute books is cause for celebration," the Executive Director of Amnesty International Zimbabwe, Jessica Pwiti, said:

The judges said the Public Order and Security Act (Posa) had been open to abuse by the state.

Judge Rita Makarau said the Posa did not "pass the test on fairness, necessity and reasonableness" and an authoritarian government "could lawfully invoke these powers without end".

Several civic groups had challenged the law in May on the grounds that it had been used unfairly to thwart freedom of assembly as guaranteed by the constitution.

Ms Pwiti said the judgement would create an environment that allows peaceful assembly, but added that police must also ensure that they respect the law.