A court of appeal in Nigeria has declared unconstitutional a law requiring every organiser of a rally to have a special police permit.
The law, a residue of colonial rule, was challenged after police used tear gas to disperse an opposition rally in the northern state of Kano in 2003.
A police spokesman told the BBC the police would adjust its procedures.
He denied allegations that Nigerian authorities had used the law to suppress opposition activities.
The Conference of Nigerian Political Parties – an opposition coalition formed when Olusegun Obasanjo was president – challenged the Public Order Act saying it was used with impunity to stifle opposition.
But Assistant Commissioner of Police Agborebi Akpoyedi said the law had helped the police keep the peace in Nigeria, especially when opposing political groups had been holding rallies at the same time.
Last month, six people were killed in clashes linked to local governmental elections in Kano.
President Umaru Musa Yar'Adua took over from Mr Obasanjo in May, after winning polls marred by fraud and violence the previous month.
BBC News
