Police in the Democratic Republic of the Congo have arrested more than 100 protesters in cities across the country who were calling for presidential elections to be held by the end of the year.
Demonstrations took place Monday in the capital, Kinshasa, the eastern city of Goma, and at least a half dozen other cities.
In Goma, witnesses said police used tear gas to disperse protesters, while in Kinshasa, media groups said several journalists covering the protests were briefly detained.
The U.N. Joint Human Rights Office in Congo condemned Monday's arrests, saying that "arbitrary arrests are incompatible with the right to information and right of freedom of assembly" guaranteed in Congo's constitution.
The youth movement Struggle for Change (LUCHA) organized the protests, timed to mark the July 31 deadline set by the country's election commission for conclusion of a voter registration program, which was not met.
The group's spokesman in Goma, Justin Muhiwa, told VOA that Congo's election commission needed to set a date for the vote because it was the right of the Congolese people to hold an election.
President Joseph Kabila's second and final constitutional mandate expired last December, leading to growing political tensions in the country.
An agreement reached last year by the president and the opposition said Kabila could remain in office until elections were organized, and it set a deadline of the end of 2017. However, the election commission announced this month that it would not be possible to organize elections by the end of December.
Kabila's government has faced a wave of protests in recent months over the election issue. Growing unrest in the country has raised fears of a return to civil war, which ravaged the DRC for nearly a decade beginning in the late 1990s, leading to the deaths of millions of people.
Austere Yalala Malivika Joseph in Goma and Mohammed Yusuf in Nairobi contributed to this report.