South Africa's governing African National Congress lost its 30-year-old outright majority in this week's election, winning only 159 seats in the 400-seat parliament, official results showed Sunday.

President Cyril Ramaphosa and the leaders of most of the rival parties attended the announcement, but in a sign he intends to challenge the result, former president Jacob Zuma stayed away.

No single party won a majority in the National Assembly. Behind the ANC's 159 seats from 40 percent of the vote came the centre-right Democratic Alliance (DA) on 87 seats and 22 percent.

In third place was Zuma's upstart radical party, the newly-formed uMkonto weSizwe (MK), which grabbed 14.59 percent of the vote and 58 seats -- but had nevertheless denounced the process.

"Our people have spoken, whether we like it or not, they have spoken," Ramaphosa said.

"As the leaders of political parties, as all those who occupy positions of responsibility in society, we have heard the voices of our people and we must respect their wishes."

The DA's leader, John Steenhuisen, has said he is ready to negotiate a coalition government with the ANC and other parties to protect South Africa from a return by Zuma to government.

Steenhuisen and other party leaders attended the results meeting hosted by the Independent Electoral Commission (IEC) but Zuma did not, having the previous night denounced the ballot as rigged.

Asked why Zuma stayed away, MK spokesman Nhlamulo Ndhlela said that to attend would be "tantamount to endorsing an illegal declaration".