Voting in Burundi's controversial elections opened Monday despite an opposition boycott and a string of grenade attacks on polling stations.
Assailants threw grenades in both the capital Bujumbura and at some provincial voting centers ahead of Monday's parliamentary and local elections, delaying the start of voting in many areas, police and election officials said.
Another grenade exploded in the capital shortly after voting began in the latest example of the weeks of violence sparked by President Pierre Nkurunzizaa's defiant bid for a third term in power.
UN Secretary General Ban Ki-moon called for the elections to be delayed after the opposition said they would not take part, as Burundi faces its worst crisis since the civil war in the country ended nine years ago.
The European Union condemned Burundi's "grave" decision to hold elections, saying it would worsen the situation.
"The organisation of legislative elections... can only exacerbate the profound crisis which is gripping Burundi," a statement Monday read.
Police patrolled the streets of Bujumbura, especially in opposition areas where the worst violence was seen during weeks of protests.
"Armed groups tried to attack polling centers... they were shooting and threw grenades, but the police stopped them," deputy police chief Godefroid Bizimana said.
In opposition areas few civilians were seen at polling stations. In some stations, the lines of people queueing were mainly soldiers or police.
"The protesters closed roads to block us, but we went with the police," said Annick Niyonkuru, one of the few civilians waiting to vote in the capital's Musaga district.
Stations for the parliamentary and local elections opened late in some areas, although election commission spokesman Prosper Ntahorwamiye insisted that, apart from some delays due to the violence, voting was "going well."
On the eve of the election, top ruling party official and parliament head Pie Ntavyohanyuma said he had joined some 127,000 other Burundians who have fled the country, denouncing President Pierre Nkurunziza's "illegal" bid to stay in power for a third term.
Burundi was plunged into turmoil in late April when Nkurunziza launched his drive for a third consecutive five-year term, triggering protests.
Opponents say his bid for another term is unconstitutional and violates a peace accord that paved the way for the end of 13 years of civil war in 2006. Presidential polls are due on July 15.
"The mandate he wants to have is illegal. I would like to say to him that forcing through the election is senseless," Ntavyohanyuma told broadcaster France 24 on Sunday.
More than 70 people have been killed in weeks of violence and a failed coup sparked by Nkurunziza's bid to stay in power, with a string of grenade attacks taking place in recent days.
Several top officials - including the deputy vice-president Gervais Rufyikiri as well as members of the election commission and constitutional court - have also fled the poverty-stricken, landlocked country.
The African Union has refused to send observers to the polls as the "necessary conditions are not met for the organisation of free, fair, transparent and credible elections."
Almost four million people are registered to vote, but the opposition are boycotting the polls, as they did in the last elections in 2010, claiming it is not possible to hold a fair vote.
Civil society groups backed the boycott in a joint statement calling on voters to skip the "sham elections" and urging the international community "not to recognise the validity" of the polls.
"This is nothing new in Burundi," election commission chief Pierre-Claver Ndayicariye said on Sunday. "In Africa, boycott is another way of doing politics."
Under the constitution, based on peace deals that ended the civil war, there are strict ethnic quotas in parliament.
Sixty percent of the parliament must be made up of members from the majority Hutu people, who make up some 85 percent of the population, with the remaining 40 percent of elected seats reserved for the minority Tutsi community.
Many fear a repeat of the civil war which split the country along ethnic lines, pitting the majority Hutus against the minority Tutsis.