An early-morning fire in Congo's capital destroyed thousands of voting machines just 10 days before the presidential election, officials said Thursday, saying the blaze appeared to be criminal in nature but vowing that it would not disrupt the vote.

Congo's first use of voting machines on Dec. 23, a rarity in Africa, has caused concerns among the opposition, diplomats and experts about possible manipulation in favor of President Joseph Kabila's preferred successor. Kabila is stepping aside after taking power in 2001.

The electoral commission said the fire broke out at a warehouse in Kinshasa, adding that it was too early to declare the cause or the extent of the damage.

Kabila's chief adviser said the fire was a criminal one and that some 7,000 voting machines and polling booths were burned. "The enemies of democracy have stepped it up a gear," Barnabe Kikaya said.

Congo's security minister said the number represents 10 percent of the voting machines for Kinshasa but added they will be replaced "very quickly."

"We cannot make quick conclusions but the criminal hypothesis is not to be dismissed," the minister, Henri Mova, said, noting that the fire had two starting points, suggesting a simultaneous beginning.

Mova was defiant in the face of a suspected effort to disrupt the election: "Those who tried it did not succeed."

Major questions remain about how Congo will be able to successfully use the voting machines in the infrastructure-starved country of 40 million voters, many without computer experience. More than 100,000 of the machines have been rolled out so far.

Campaigning in the final days before the vote has turned violent this week. Security forces opened fire on supporters of opposition candidate Martin Fayulu on Wednesday in Kalemie, killing a young woman, said Ida Sawyer, deputy Africa director at Human Rights Watch.

That followed similar reported violence in Lubumbashi. On Wednesday, the United Nations peacekeeping mission in Congo said the special representative of the U.N. secretary-general deplored the deaths and urged Congolese authorities to take the necessary steps to void further violence, noting "obstacles encountered by some opposition candidates during their efforts to hold public meetings in certain cities around the country."

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