Cape Town – The Zimbabwean government has reportedly taken a swipe at Botswana President Ian Khama, who this week called on ageing President Robert Mugabe to step down.In an interview with Reuters, Khama said Zimbabwe could not come out of its current hardships under the leadership of Mugabe, 92.He said the southern African country had more than enough strong leaders, who could take over from Mugabe and lead the country out of its continued woes. "They have got plenty of people there who have good leadership qualities who could take over. It is obvious that at his age and the state Zimbabwe is in, he’s not relly able to provide the leadership that could get it out of its predicament," Khama was quoted as saying. But according to the state-owned Herald newspaper, Zimbabwe’s information minister, Chris Mushowe, said Khama’s sentiments were "taboo in African etiquette and diplomatic parlance"."The government of Zimbabwe is shocked by this uncharacteristic behaviour of president Khama, who until last month was at the helm of SADC, and should know better that you don’t use the media platform to criticise fellow SADC leaders as he has just done with president Mugabe."It is a taboo in African etiquette and diplomacy," Mushowe was quoted as saying. Khama has on several occasions, openly criticised Mugabe.He was the only African leader who stood with Western countries in 2013 following an "overwhelming" victory by Mugabe and his ruling Zanu-PF party in elections that were dismissed by opposition parties as a "farce".