In Douala, barricades burned and gunfire echoed through the streets as security forces clashed with protesters denouncing what they called a stolen vote.
At least four people were killed and more than a hundred arrested as anger swept through major cities.
Opposition supporters, led by Issa Tchiroma Bakary, claimed the election was rigged and demanded transparent results.
The unrest left neighbourhoods paralysed and fear spreading fast, with residents describing scenes of chaos.
Although tensions have eased in recent days, the situation remains fragile, with sporadic clashes still reported on 28 October.
