Burundi's government said on Thursday that weeks of protests against a third term bid by the president were over, claiming that the remaining demonstrators were only being organized by journalists.

Opposition leaders however said the protests continued, calling the government claims "pure lies" with now just over two weeks before parliamentary elections are due.

Burundi will go ahead with parliamentary elections on June 29 and a presidential poll on July 15, the presidency announced Wednesday, confirming a delay in the votes caused by weeks of civil unrest.

Opposition leaders, however, said it was impossible to hold fair polls while "people are murdered".

Burundi's government defied opposition demands Tuesday for President Pierre Nkurunziza to end a third-term bid for power, as the U.N. warned the country risked being "catapulted" back into civil war.

"This decision is non negotiable," government spokesman Philippe Nzobonariba said in a radio broadcast, dismissing opposition demands the president step down.

Once a symbol of ethnic unity in post-civil war Burundi, the army is now deeply divided and faces a growing climate of fear after a failed coup by generals in the central African nation.

Burundi was plunged into crisis when President Pierre Nkurunziza announced a controversial bid for a third term in April, leading to deadly street protests and an attempted coup in mid-May, which laid bare political splits within the military.

Police in Burundi on Friday shot dead a protester in the capital amid renewed demonstrations against President Pierre Nkurunziza, witnesses and a local official said.

Residents in Bujumbura's Musaga district, which as been at the center of protests against the president's controversial bid to stand for a third term, said a group of around 200 people tried to gather in the area to kick-start the flagging protest movement.

An aide to Burundian President Pierre Nkurunziza on Thursday called for "a frank and constructive dialogue" with the opposition, who have driven weeks of street protests against his bid to stand for a third term.

Nkurunziza's communications advisor, Willy Nyamitwe, said although the government considered the president's bid to be perfectly legal, he said for the first time that the matter was not "taboo".

Rwanda's Green Party, the country's tiny but main opposition, said Thursday it was challenging moves to change the constitution to allow strongman and President Paul Kagame to stand for a third consecutive term in elections in 2017.

"We submitted a lawsuit to the Supreme Court yesterday, demanding the court block parliament from any future plans to reform the constitution, especially article 101 about the lifting of presidential term limit," party president Frank Habineza told AFP.

Burundi's parliamentary polls scheduled for Friday will be postponed until a new date is set by the electoral commission, an aide to the president said, with the country rocked by weeks of political crisis.

"It is sure. There will be no elections on Friday," Willy Nyamitwe told AFP on Wednesday.

Opposition parties in Burundi said Wednesday they are ready to resume talks to find a solution to the weeks-long political crisis triggered by President Pierre Nkurunziza's controversial third term bid.

A group of 17 political parties and organizations issued a joint statement reaffirming their "commitment to continued dialogue" aimed at ensuring "free, calm, transparent and credible elections".

Protesters in Burundi once again defied police on Tuesday as they began a 38th day of demonstrations against President Pierre Nkurunziza's plan to run for a controversial third term.

Police fired live rounds and tear gas to break up groups of demonstrators trying to gather in the three hotspot neighborhoods of Cibitoke, Musaga and Nyakabiga in the capital Bujumbura, AFP correspondents said.