Zimbabwe's president has spoken of his anger that his embattled deputy Joyce Mujuru allegedly plotted to assassinate him and accused her of being a thief.

Speaking at the ruling Zanu-PF party's congress, Robert Mugabe said he would act against all corrupt officials.

Mrs Mujuru's absence from the congress showed she was "scared", he added.

Recently expelled Zanu-PF member Robert Gumbo told the BBC the 90-year-old leader had "completely" turned the party into his "personal property".

Mr Mugabe had targeted Mrs Mujuru to advance the "fortunes" of his wife Grace, the former Zanu-PF spokesman added.

Mrs Mujuru, who has previously denied the allegations, had been seen as a potential successor to Mr Mugabe, with whom she fought for Zimbabwe's independence from white-minority rule.

However, her career ran into trouble when Mrs Mugabe entered into politics this year, and accused her of plotting against her husband.

The congress, being held in the capital Harare, is expected to elect the first lady as the head of Zanu-PF's women's wing.

'Bribing delegates'

Mr Mugabe, who has ruled Zimbabwe since independence in 1980, will remain as Zanu-PF leader.

He told thousands of delegates that he welcomed the fact that his wife had exposed Mrs Mujuru's attempt to oust him.

"Thieves never succeed... look at all the transgressions. Her corruption is now exposed," Mr Mugabe said.

Mr Mugabe, while speaking in the local Shona language, said Mrs Mujuru planned to assassinate him but in English he only accused her of trying to have him "kicked out" by bribing delegates.

"But you delegates are not foolish. You can't be bought," Mr Mugabe added.

Vowing to tackle corruption, Mr Mugabe said: "If you were a minister, you will lose your job. Some will face the full might of the law."

Mrs Mujuru was first accused in the state-owned media of plotting to kill Mr Mugabe and has instructed her lawyers to take legal action to clear her name.

Referring to her and her allies' failure to attend the congress, Mr Mugabe said: "As you see we have empty spaces on the stage. We didn't chase them away but they chose not to come."

Correspondents say Justice Minister Emmerson Mnangagwa is now among the candidates being tipped to succeed Mrs Mujuru, her long-time rival.

Mrs Mujuru took part in the 1970s guerrilla war against white-minority rule when her nom de guerre was Teurai Ropa (Spill Blood).

She married Solomon Mujuru, the former army chief seen as Zimbabwe's king-maker in 1977. He died in a fire at his farm in 2011.