Angolan opposition supporters took to the streets on Saturday to protest the return to power of the long ruling MPLA party in divisive elections last month.

The demonstrations were called by UNITA -- the largest opposition party and a former rebel movement which fought a 27-year civil war against the MPLA government that ended in the oil-rich country in 2002.

The opposition National Union for the Total Independence of Angola (UNITA), whose popularity has been growing in recent years rejected the results of the August 24 vote.

It challenged the outcome in court, but the country's top court dismissed the petition.

More than 2,000 protesters marched, some brandishing placards inscribed with slogans such as "respect for the peoples vote" and waving UNITA flags in downtown Luanda.

"Today we are a national consensus," said charismatic UNITA leader Adalberto Costa Junior, addressing the crowd to rapturous applause and chants of "president Adalberto".

"The court has come out badly damaged because everyone knows who really won the elections," he added.

The formerly Marxist Popular Movement for the Liberation of Angola (MPLA) won a wafer-thin majority of 51.17 percent of the vote, handing President Joao Lourenco, the 68-year-old former general, a second term in power.

It was the MPLA's worst electoral showing since independence from Portugal in 1975.

UNITA proved popular in urban areas and among young voters eager for economic change.

"The MPLA must understand that there are other voices they have to listen to," Maria Saraiva, a 33-year-old unemployed hairdresser told AFP at the start of the march.

Costa Junior, 60, who has been credited with reinvigorating the opposition in Angola, told young people on Saturday that "your presence here is an example of courage and this is the beginning of a march for the future".

Opposition parties and civic groups had said the vote was marred by irregularities. 

"Today is the first of many steps we as UNITA sympathisers will take to force political changes," said sound engineer Jose Costa, 46.