A political divide between Congo's eastern and western regions is threatening to destabilise presidential and legislative elections, as chaotic scenes of vote-counting unfold across the country amid accusations of fraud.

Last Sunday's elections were Congo's first in more than 40 years and seen as a crucial step after decades of dictatorship and years of war that sucked in several neighbouring countries and killed millions. The elections, overseen by the United Nations, have cost international donors about $450m (€350m, £236m).