More than 30 pro-democracy activists have been arrested in the Democratic Republic of Congo after holding a protest against the planned use of controversial new voting machines in the presidential election, which is due in December.
The activists from the organisation, Lucha, were also calling for a review of voters' lists.
The Congolese police said they had released some of the demonstrators.
There are also reports of arrests at similar protests in the cities of Goma, Lubumbashi and in Kasai Province.
Correspondents say there is increased tension in the country, especially after the authorities barred two prominent opposition politicians from running.
A prominent leader of Lucha, Luc Nkulula, died in a mysterious fire in June.
In an obituary in the UK Guardian newspaper, journalist Ruth Maclean wrote:
"He died as he had lived: thinking first of Lucha, the movement he and other fearless young Congolese had built, enduring arrests, beatings and repression in order to further their ideals of democratic change and creating a future for the youth of the Democratic Republic of the Congo."