Police in the Burundian capital used water cannon and tear gas on Sunday to disperse protesters demonstrating against President Pierre Nkurunziza seeking a third term, witnesses said, after the government banned protests for or against the move.

Witnesses at the protests said at least one police officer and a protester were injured.

Burundi's ruling CNDD-FDD party nominated Nkurunziza as its presidential candidate on Saturday, prompting hundreds of civil society groups to decry the move as a "coup" against the constitution, which limits leaders to two terms in office.

"We deplore the way police acted with violence against a peaceful demonstration," said Janvier Bigirimana, a civil society activist.

Interior Minister Edouard Nduwimana said the demonstrations were illegal because the government had banned any protest for or against the president seeking a third term.

"We have asked whoever is against the third term to follow legal procedures. Only the constitutional court can judge if Nkurunziza has the right to run or not," he told Reuters.

More than 300 civil society organizations have called for demonstrations and a leading opposition politician has asked Nkurunziza to reconsider.

Dozens of protesters gathered in four suburbs of the capital Bujumbura and set off to reach the city center for a march, but riot police blocked their path.

INTERNATIONAL PRESSURE

Burundi's constitution says the president is elected for a five-year term that can be renewed only once. Nkurunziza's supporters say his first term should not count because he was chosen by parliament rather than by a popular vote.

African leaders and Western nations have urged Nkurunziza not to run. The United States and the European Union indicated they could take steps if violence erupted.

Those opposed to a third term also say it goes against the spirit of a peace deal that has kept Burundi calm for a decade since an ethnically-fueled civil war ended in 2005.

Tanzania brokered the Arusha peace deal in 2000 to end fighting between the Hutu and Tutsi ethnic groups in the tiny east African coffee-growing nation.