Nineteen pro-democracy activists arrested during a protest against the Democratic Republic of Congo's President Joseph Kabila were released Tuesday, their organisation and a UN official said.
"Lucha confirms that 18 comrades arrested during a sit-in in Goma (in eastern DR Congo) on December 21 ... were released on Tuesday," the opposition movement's Ghislain Muhiwa said.
"Another Lucha activist, Gloria Senga, who had been kidnapped on December 18 in Kinshasa, has also been freed," he said.
Seven other Lucha activists are still behind bars, he added.
The director of the United Nations Joint Human Rights Office in DR Congo, Jose-Maria Aranaz, confirmed the Lucha members' release, but said he was "concerned" about the fate of other activists still held by the authorities.
Lucha members and other opposition activists have staged a string of protests in recent months demanding that Kabila, whose mandate ended on December 20, step down.
Despite being constitutionally banned from seeking a third term, a controversial order by the constitutional court said Kabila could stay on until a successor was elected.
The UN said Friday that at least 40 people had been killed and another 460 arrested last week during protests as Kabila's mandate came to an end with no sign of an election or of him stepping down.
Human rights groups have repeatedly called on Kabila's government to ensure opposition activists are not targeted, and to respect the right to free expression and assembly.
In another development, the regional parliament of Haut-Katanga province in the southeast of the country voted to lift an opposition MP's immunity, after he was accused of insulting the president.
The courts are seeking to prosecute Gabriel Kyungu Wa Kumwanza over claims he insulted Kabila in a recording whose content has never been made public -- and whose very existence the MP disputes.