Burundi has been hit by a new wave of protests in opposition to President Pierre Nkurunziza's re-election for a third term.
Burundi's constitution stipulates that a president can only serve for two terms, but Nkurunziza's party says he is eligible for another term since his first term was decided by lawmakers.
Thousands of Burundians have fled to neighboring Rwanda fearing violence. According to the Guardian, many people claim to have left Burundi due to growing pressure to support Nkurunziza’s party.
Hundreds remained in Burundi to protest against the ruling party’s decision to nominate the president to run for a third term.
More than 24,000 people have fled Burundi this month, as tensions mount ahead of presidential elections in June, the UN refugee agency said.
This includes 5,000 who crossed into Rwanda at the weekend, it added. The U.S. government has criticised the ruling party's decision.
"With this decision, Burundi is losing an historic opportunity to strengthen its democracy by establishing a tradition of peaceful democratic transition," the State Department said in a statement.
“There were clashes between protesters and armed police in Bujumbura, the nation's capital. Police fired tear gas to disperse crowds and also blocked access to some parts of the city” witnesses told the AP.
The protests are the biggest in Burundi since the civil war ended in 2005. The Red Cross says at least six people have been killed in the demonstrations since Sunday.
BBC Burundi analyst Prime Ndikumagenge says the phone lines of private radio stations have been cut, a decision apparently taken by the authorities to prevent news of protests from spreading.
The ruling party's Vice-President Joseph Ntakirutimana has compared one radio station to a former Rwandan broadcaster accused of fuelling the 1994 genocide.
Burundi's former-President Pierre Buyoya, who was involved in the peace process that ended more than a decade of ethnic conflict has warned that Burundi could return to war if the crisis is not resolved.
UN chief Ban Ki-moon said, in a statement, that he had dispatched his special envoy for the region, Said Djinnit, to Burundi for talks with Mr Nkurunziza.
The crisis is also due to be discussed later at a meeting of the African Union's Peace and Security Council.
An estimated 250,000 people died in Burundi from the combined conflicts between Hutu and Tutsi groups since 1962. People fear that today’s conflict may start another civil war.