Libreville - Gabon's presidential election "lacked transparency", the head of the 73-strong EU electoral monitoring team in the country said on Monday, a day before the official results were due out.
Speaking to reporters in the capital Libreville, Bulgarian MEP Mariya Gabriel said Saturday's vote in the oil-rich Central African country, was "managed in a way that lacked transparency".
"The mission condemns the lack of transparency in the electoral bodies which failed to make essential information available to the campaigns, like the electoral roll or a list of polling stations," she said.
The EU observers said that a week before the election only half of voters had received their ballot cards.
The remarks came after a bitterly disputed election in which both sides accused the other of electoral fraud.
Official results will not be published until Tuesday, and there are fears that the tensions may erupt into a repeat of the violence seen after the disputed 2009 election.
Opposition candidate Jean Ping, who has claimed victory in the vote which pitted him against the incumbent Ali Bongo, on Monday accused the Cenap national election commission of "manipulation" and tampering with the outcome of the poll.
"The people of Gabon, who have mobilised massively... and want me to run the country will never accept having the victory, their victory, stolen from them," the 73-year-old said at his campaign headquarters in Libreville.
"(They) will defend by all means the victory that civil and military hawks now want to steal," he said, flanked by figures formerly associated with the Bongo regime who have supported his campaign.
UN urges restraint
Ping also vowed to "guarantee complete security" for Bongo and his family if he stepped down from the presidency and pledged there would not be a "witch hunt" once he had departed.
United Nations secretary general Ban Ki-moon on Monday urged both sides to avoid commenting on the results until they are announced officially.
The EU monitoring team said that in the run-up to the election, incumbent Bongo enjoyed an unfair advantage over his rivals.
"Before the official start of the campaign, the mission observed a confusion between the campaigning activities and (Bongo's) official duties," they said.
Media coverage was heavily skewed in favour of Bongo to the detriment of his opponents, including Ping, the EU mission added.
The Gabonese interior ministry reacted by focusing on the "positives" in the EU mission report, "despite some irregularities".
The ministry declared itself satisfied that the European observers had found that "in around 95 percent of the 260 polling stations observed the voting conditions were judged satisfactory".
"The voting went ahead calmly and peacefully, without major incident, and secret balloting was ensured," the interior ministry added.
Ping worked for many years in the administration of Omar Bongo, Ali's father. He also served as head of the African Union Commission and president of the UN General Assembly.
After his claim of victory on Sunday, Bongo responded by saying that he was "calmly" awaiting the results while his supporters said that it was "dangerous and illegal" to declare a victor before the official announcement.
Presidential spokesman Alain-Claude Bilie-By-Nze claimed that Bongo "was ahead with a lead that could not be overturned".
Fearing a repeat of the violence that followed Bongo's victory in 2009, many residents have stocked up on food and are staying indoors.
On Sunday, the streets of Libreville were deserted and shops and stalls that are usually open were closed.
The embassy of former colonial power France warned its citizens not to travel within the country unless absolutely necessary and to keep themselves informed.
"We want to get the results soon," said a man in Libreville called Honore.
"We'll see how the candidates react. I hope it won't be like last time."
In 2009, several people were killed in clashes, buildings were looted and the French consulate in Port Gentil, which saw the worst of the violence, was torched.
Ping's campaign coordinator, Jean Gaspard Ntoutoume Ayi, has previously claimed that Bongo would attempt to retain power by force.