By Clement Manirabarusha and Goran Tomasevic
BUJUMBURA (Reuters) - Burundi's opposition boycotted peace talks with the government on Monday in protest at the killing of an opposition leader, despite U.N.-led calls for dialogue to end a month of protests and violence in the east African country.
Rights groups say at least 20 people have died since protests broke out on April 26, a day after President Pierre Nkurunziza announced he would seek a third five-year term.
U.N. Secretary-General Ban Ki-moon and others have condemned the killing by unidentified gunmen on Saturday of Zedi Feruzi, whose small UPD party is part of a wider opposition that says the president is breaking the two-term limit set down in the constitution.
Some opposition and civil society groups started withdrawing from the talks on Sunday. The rest pulled out on Monday in protest at the assassination of Feruzi, presidential spokesman Gervais Abayeho said.
"The government remains open to talks and the government hopes they will heed the call by the international community to resume talks so that a lasting solution can be found to the current crisis," Abayeho said.
One activist involved in the talks said the opposition wants the government to allow peaceful protests, the police to stop killing demonstrators and for arrested protesters to be freed, indicating talks could be resumed if these conditions were met.
"The police are still shooting at protesters, and arrested protesters are still in jail," said Pierre Claver Mbonimpa, president of the Association for the Protection of Human Rights and Detainees.
The protests have triggered the biggest political crisis in Burundi since the end of a ethnically charged civil war in 2005. Diplomats fear that, if left unresolved, it could lead to another bout of bloodletting between the Hutu and Tutsi communities.
Some 800,000 mainly Tutsis and moderate Hutus were slaughtered in a 1994 genocide in neighboring Rwanda. The current unrest has prompted more than 110,000 Burundians to flee into Rwanda, Tanzania and Democratic Republic of Congo for fear that violence will spread outside the capital, Bujumbura.
Chad's President Idriss Deby, speaking at an economic summit of central African states on Monday, urged Nkurunziza and "the whole political class and civil society to pursue the path of dialogue".
A Reuters photographer in the flashpoint Cibitoke district of the capital said about 200-300 protesters hurled rocks at the police but were dispersed when the army fired warning shots over their heads. Earlier, police fired teargas at protesters.
"What we are against is the third term, and all the killings by the police... should stop," said one demonstrator in Kirundi, another Bujumbura suburb where protesters took to the streets.
The government has called the protests an "insurrection" and linked them to a failed coup by some army officers earlier this month.
Nkurunziza's supporters point to a recent constitutional court ruling saying he can run for a third five-year term. They argue his first term does not count toward the two-term limit because he was picked by parliament, not by popular vote.
The presidential election is scheduled for June 26, while parliamentary and local council polls are due on June 5, after a delay of just over a week because of the unrest.
(Additional reporting by Reuters TV, Madjiasra Nako in N'Djamena, and Drazen Jorgic in Nairobi; Writing by Drazen Jorgic; Editing by Mark Trevelyan)