South Africa's parliamentary speaker has apologised for calling an opposition MP "a cockroach".

Baleka Mbete made the remarks about Julius Malema at an ANC rally, after ordering him and other Economic Freedom Fighters (EFF) MPs out of parliament.

Mr Malema was protesting during Jacob Zuma's State of the Nation address.

The EFF leader claims that the remark was a threat, saying: "We know what happened to people called cockroaches in Rwanda."

The term "cockroach" was used in Rwandan radio broadcasts to urge ethnic Hutus to kill Tutsis in the 1994 genocide, in which 800,000 people were slaughtered.

The main opposition party, Democratic Alliance, has called for Ms Mbete to step down. Their MPs walked out of parliament after security forces clashed with and expelled EFF members, on the speaker's orders last week.

Two days later, Ms Mbete, chairwoman of the governing African National Congress (ANC), told a party rally that Mr Malema was a "cockroach", adding that President Zuma's speech was a "beautiful opportunity" to "deal with those irritants".

Ms Mbete said she was now withdrawing her remarks "unreservedly".

"I apologise unconditionally, to South Africans, to Parliament and Honourable Julius Malema for any hurt or harm I may have caused," she said.

The EFF used President Zuma's annual State of the Nation speech to question him about a state-funded, multi-million dollar upgrade to his private residence.

Mr Malema was ordered to leave when he demanded the president "pay back the money" from the upgrade to his home.