|Thousands have been internally displaced following weeks of violence triggered by the political standoff [AFP]
Ban Ki-moon, the United Nations secretary-general, has expressed concern over the reported delivery of three attack helicopters by Belarus to Cote d'Ivoire for use by forces loyal to incumbent president Laurent Gbagbo.
Ban's office said the delivery, marked a "serious violation" of an arms embargo in force against the west African nation since 2004.
But Andrei Savinykh, a Belarusian foreign ministry spokesman, said claims that his country had violated the UN arms embargo were "groundless".
Diplomats said Ban's allegation was based on reports he had received from the UN peacekeeping mission in Cote d'Ivoire.
Speaking on condition of anonymity, the diplomats said that neither the UN Department of Peacekeeping Operations nor the Security Council's so-called Group of Experts that monitors sanctions violations could confirm the allegation.
Cote d'Ivoire has been gripped by a political crisis since Gbagbo refused to cede power to Alassane Ouattara, the internationally recognised winner of November's presidential elections.
The reports of the delivery of attack helicopters come after a week of street fighting in the main city of Abidjan which left dozens dead and prompted the UN to warn that the country was on the brink of a new civil war.
The first delivery of military equipment reportedly arrived on Sunday evening and additional flights were scheduled for Monday, according to the UN.
Ban called for "full compliance" with the embargo and warned that both the supplier of the military equipment and Gbagbo would face "appropriate action".
The UN, which has stationed peacekeepers in Cote d'Ivoire since 2004 following the end of the country's civil war, has been providing 24-hour protection to Ouattara since November.
He has been confined to the grounds of a heavily guarded hotel because Gbagbo refuses to leave office.
The three-month standoff has already claimed the lives of hundreds of Ouattara supporters, victims of targeted assassinations and "disappearances", according to UN investigators and human rights groups.
The conflict reached a new level of intensity last week when commandos allied with Ouattara infiltrated the Abidjan district of Abobo, killing seven policemen in the clashes that followed.
The violence in Abobo also resulted in the disruption of state television broadcasts in Abidjan.
On Sunday witnesses reported seeing a steady stream of families leaving Abobo, watched over by UN peacekeepers in armoured vehicles.
The UN mission said three peacekeepers were wounded when they were shot at while patrolling the area and accused Gbagbo supporters of carrying out an ambush amid violence against peacekeepers on Friday and Saturday.
The Associated Press also reported a leaked UN report as saying that two UN employees of Ukrainian descent had been kidnapped by the Young Patriots, an armed youth movement allied with the country's sitting president.
Major powers and most African neighbours have recognised Ouattara as president, but Gbagbo has refused to step down, citing a decision by the country's constitutional council to declare the vote rigged and hand him victory.
The crisis has also sparked concerns over supplies of cocoa from Cote d'Ivoire, the world's largest cocoa grower.
The European Union has banned its ships from docking at Ivorian ports and exporters have largely followed a call by Ouattara for a temporary embargo on cocoa supplies.
Other sanctions have paralysed the country's banking sector, crippling the economy and prompting some analysts to forecast a fall in gross domestic product until the crisis is over.