An opposition party in Burundi says 200 of its members were arrested on Election Day on Wednesday.
The National Freedom Council spokesperson Terence Manirambona says the arrests continued into Thursday.
Most of those arrested were observers at polling stations, in every province of the country, he told BBC Great Lakes.
Police have not commented on the arrests but earlier a spokesperson said general election day had been generally peaceful.
Meanwhile, social media users in Burundi were able to reconnect to Twitter, WhatsApp and Facebook on Thursday, ending an outage that started on Wednesday morning.
President Pierre Nkurunziza is stepping down following 15 years in power, during which his government has repeatedly been accused of serious human rights abuses.
National Freedom Council’s leader and presidential candidate Agathon Rwasa is considered the main challenger to the ruling party’s Evariste Ndayishimiye.