2 protesters shot dead in Burundi clashes

Two protesters were shot dead in clashes with police in Burundi on Sunday, in a violent escalation of a crisis over an attempt by the country's president to cling to power.

Clashes erupted in the capital Bujumbura a day after the ruling CNDD-FDD party, which has been accused of intimidating opponents, designated President Pierre Nkurunziza as its candidate for the June 26 presidential election.

The president has already been in power for two terms, and opposition figures and rights groups say his attempt to stay put is unconstitutional. They also vowed to step up protests on Monday.

There are fears the worsening crisis could plunge the Great Lakes nation -- which only emerged from a long and bloody civil war in 2006 -- back into violence.

Eyewitnesses said one person was shot dead in the capital's Ngagara district and another in Musaga after police used live ammunition to disperse crowds defying a government ban on protests.

"We had called for peaceful protests and that is what happened, but the police and ruling party militia fired real bullets at the protesters," said Leonce Ngendakumana, an opposition leader.

Local media reports said several more people were wounded, with several police also hurt while trying to prevent thousands of demonstrators marching on the city centre.

Dozens of people were arrested, witnesses told AFP, with police using tear gas, batons and water cannons spraying water dyed blue to mark demonstrators.

Burundi's Interior Minister Edouard Nduwimana condemned what he said were "uprisings called for by certain politicians and civil society".

Authorities also cut transmissions outside of the capital by the country's three main independent radio stations, including the influential African Public Radio (RPA), which has for months been reporting on government intimidation of opponents.

"The government says we are inciting people to rise up by reporting live from the protests," said Patrick Nduwimana, head of a grouping of Burundian broadcasters.

He told AFP the move was "a serious violation of the right to information".

- Call for bigger protests -

Nkurunziza's opponents urged even bigger protests on Monday.

"We are calling on residents of Bujumbura to protest against the third mandate for Pierre Nkurunziza in even greater numbers tomorrow," said Vital Nshimirimana, head of a prominent NGO forum and the main leader of the campaign to block a third term.

"The campaign against a third term also urges parents not to send their children to school and for shops to close as a sign of solidarity... and so they do not fall victim to Burundian police who shoot blindly into crowds," he told reporters.

Tensions in Burundi have been mounting for months as Nkurunziza -- a former rebel leader, born-again Christian and football fanatic who has been president since 2005 -- lays the ground for a third term.

Opposition groups, who boycotted the last elections in 2010 over allegations of fraud, say his re-election bid violates the constitution as well as the peace deal that ended the civil war.

The influential Catholic Church has also spoken out against the president's plans to stay put, while UN rights chief Zeid Ra'ad Al Hussein has warned that the country is at a "crossroad" between a fair vote and a route back to its "horrendously violent past".

On Saturday, Washington condemned Nkurunziza's candidacy and warned the country was "losing an historic opportunity to strengthen its democracy."

After Sunday's protest deaths, the African Union appealed to Burundi's government to "exercise the highest restraint and protect the population"

It also called for all parties "to work toward preserving Burundi's hard-earned peace."

At least 15,000 Burundians have fled the country to neighbouring Rwanda in recent weeks, according to the latest figures from the UN's refugee agency, which has warned that those numbers could swell "with more political tension rising and more acts of violence being reported."

Many are fleeing threats by the pro-government militia Imbonerakure, the youth wing of the ruling CNDD-FDD party. Rights groups allege that the militia has been armed and trained over the past year in order to help Nkurunziza stay in office.