Kinshasa, Aug 1, 2006  - A leading presidential candidate in the Democratic Republic of Congo (DRC) added his voice on Tuesday to allegations of irregularities in the elections here but the two main contenders and international observers remained satisfied with the poll.

Azaria Ruberwa, who is also one of four vice presidents, alleged "massive fraud" in the presidential election, mostly in favour of incumbent Joseph Kabila. He demanded a new vote be held "in all polling stations where serious irregularities were noted".

Ruberwa, head of the Congolese Rally for Democracy (RCD), a former Rwandan-backed rebel group, accused "representatives of the CEI (Independent Electoral Commission) of acting like political militants".

He alleged irregularities in the capital Kinshasa, as well as in the east of the country, the centre, the northeast and the southeast.

On Monday several minor candidates, including the son of former dictator Mobutu Sese Seko, also alleged serious irregularities in Sunday's presidential and parliamentary elections -- the first multi-party elections since the eve of independence from Belgium 46 years ago.

But the two leading candidates, Kabila and rebel-turned-politician Jean-Pierre Bemba, still appeared to be happy with the polls. And international observers continued to urge candidates to respect the outcome and lodge any complaints via official channels.

A spokesman for Kabila told AFP on Tuesday that it was up to the DRC's Supreme Court to rule on complaints, while a spokesman for Bemba's party said that although some "worrying things" had been noted, this was just the result of "inexperience and clumsiness".

The United Nations mission in DR Congo said on Tuesday that the election had been "satisfactory".

"Some difficulties of a logistical nature, as well as some isolated incidents were certainly deplored, in particular in the two provinces of Kasai and Kinshasa. But overall the results are satisfactory and sometimes went beyond all expectations," it said.

The Carter Center, the human rights group founded by former US president Jimmy Carter which sent a 58-member team to observe the elections, said on Tuesday that the irregularities "appear to be minor".

Hwoever, some deficiencies in procedures had weakened important safeguards designed to verify voters' identities, it said.

A foreign diplomat in Kinshasa said that the fraud allegations were from candidates on the losing side frightened of losing power.

"They are realising that they are going to disappear from the political landscape," he said on condition of anonymity.

By early Tuesday ballots in 90 percent of districts had been processed and results posted on the doors of polling stations, CEI vice president Norbert Basengezi told AFP.

The final nationwide count is not expected for three weeks though, because voting was still underway in some districts and because the DRC's vast size and weak infrastructure are slowing down the nationwide count.

Turnout figures are not yet known but the CEI's Basengezi said participation had been high throughout the country and international observers said had been impressed by voter numbers.

Voting was extended into Monday in 226 districts in the central province of Kasai, where the process was disrupted after supporters of a party that boycotted the polls threw stones and torched polling stations at the weekend.

Another 12 districts near Mweka in western Kasai were still open on Tuesday.

Basengezi said the Supreme Court would examine complaints of fraud but added that the DRC could be proud of the elections.

"Over the last 40 years, there have been very few African countries that have carried out elections with this degree of transparency," he said.

"Parties have been allowed to have observers present at each stage of the process, from the vote to compiling the results," he stressed.

Meanwhile praise for the relatively peaceful polling continued to pour in from around the world.

"This historic event is a milestone in the country's peace process," UN Secretary General Kofi Annan said through a spokesman.

He congratulated the Congolese people "for their broad participation and for the peaceful conduct of the elections".

The UN Security Council nevertheless on Monday unanimously extended for another year an embargo on weapons destined to foreign and domestic armed groups in the DRC.

South African President Thabo Mbeki, whose country mediated in the peace accord that ended the 1998-2003 regional war centred on the DRC, also had praise for the central African country.

"I take this opportunity to pay tribute to the Congolese religious community and all political parties for massively mobilising all sectors of society to participate in the making of history," Mbeki said.