Murders in South Africa have surged by more than 7% in the last year, with more than 20,000 people killed in 12 months, new official statistics have shown.

The country has long struggled to with violent crime. The new figures, released on Tuesday, showed that 57 people were murdered daily over a 12-month period between April 2017 and March 2018.

“It borders close to [a] war zone while there is a peace,” said Bheki Cele, the police minister.

He added: “We haven’t reached a state of lawlessness in South Africa and we won’t … This situation must be reversed with lightning speed.”

The rise in the total was the biggest single increase since the end of the racist apartheid regime 24 years ago, experts said.

The statistics will weaken efforts by President Cyril Ramaphosa, who took power in February, to attract overseas investment to South Africa and to boost the country’s tourist industry.

But the statistics will also undermine claims from local and international rightwing organisations – echoed by Donald Trump in a controversial tweet last month – of the “mass killing” of white farmers in South Africa.

Between April 2017 and March 2018, police recorded 62 murders during 58 attacks on farms in South Africa. Fifty-two victims of fatal attacks were the owners or occupiers, nine were farm workers and one was a farm manager. Forty-six of the murder victims were white.

The statistics show a significant rise in sexual offences, to 50,108, up from 49,660 in 2016-17. The majority of the sexual offences recorded were rapes.

There was however a decrease in the number of burglaries from residential properties, shoplifting and arson. Overall reported crime was down by more than 4%.

Cele, who served as the national commissioner of the South African police service until October 2011 when he was suspended from duty following graft allegations, said that South Africans should not have to “take it as a norm that when on the road, you must be hijacked, or when at home, someone must break in and terrorise you and your family”.

Gareth Newham, an expert in crime at the Institute for Security Studies in Pretoria, said murder rates were considered the most reliable indicators of violence in South Africa and the rise was “a red flag, a wake-up call”.

Newham praised the willingness of Cele to focus on the murder rate. “It was a new approach. He did not bury his head in the sand and showed a willingness to do things differently. That is a reason to give us hope,” he said.

Experts attribute the 17% rise in the murder rate over last five years – after a 55% drop over previous 17 years – to a range of factors including corruption in the police force, appointments to senior posts in law enforcement that prioritised loyalty to political leaders over competence, and a deteriorating economic environment.

Last week official statistics surprised most observers by revealing the country was in recession. The currency crashed to below its level before Ramaphosa took power and the prospect of a potentially catastrophic downgrade by ratings agencies now looms. Forecasts put real economic growth at less than 1% this year.

Unemployment – already very high – is rising and inflation is hitting poor people’s budgets hard. Inequality is a significant factor in fuelling crime of all types in South Africa, successive studies have shown.

“We are not going to reduce property crime or violence if we do not get our economy growing. [But] there are other countries with worse economies than ours and they do not have anywhere near the murder rates we have. We cannot just police this down,” said Newham.