JOHANNESBURG (Reuters) - Former South African main opposition leader Helen Zille will face a disciplinary process by her Democratic Alliance (DA) party after saying on Twitter on Thursday that the legacy of colonialism was not all negative.

FILE PHOTO - South African opposition Democratic Alliance leader Helen Zille (C) speaks to the media before casting her vote in Rondebosch, Cape Town, May 7, 2014. REUTERS/Sumaya Hisham

The incident caused a public outcry, with critics saying Zille’s comments risked fanning the racial tensions that endure more than two decades after the end of apartheid rule. The ruling ANC denounced her words as reckless.

“For those claiming legacy of colonialism was ONLY negative, think of our independent judiciary, transport infrastructure, piped water etc,” Zille, a white South African, said on Twitter.

“Would we have had a transition into specialized health care and medication without colonial influence? Just be honest, please,” she said in a later tweet.

South Africa was colonized by the Dutch and the British for about 300 years. The country then experienced white minority rule under apartheid.

Zille, who is the premier of the Western Cape province, has apologized but her party leader condemned her comments.

“She should face a disciplinary process in the party,” Mmusi Maimane told 702 Talk Radio. “Her actions, her statement was completely unacceptable and indefensible,” Maimane added.

Maimane, who took the reins as the DA’s first black national leader in 2015, last year led the party to strong gains in a local election, taking the capital Pretoria and commercial hub Johannesburg from the ruling African National Congress (ANC).

The DA has a strong following among white South Africans.

The ANC urged Maimane and his party to remove Zille from her position immediately over “her reckless and ignorant claims” on colonialism.

The DA last year revoked the membership of Penny Sparrow after a Facebook post in which she referred to black people as “monkeys” went viral. A court later ordered Sparrow to pay 150,000 rand ($11,780) to charity after she was found guilty of hate speech.

Standard Bank economist Chris Hart resigned last year after he tweeted in January that black people had “a sense of entitlement and hatred towards minorities”.

White senior judge Mabel Jansen was publicly criticized over racist comments about black culture and rape.

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