Security agencies are on high alert to ensure that xenophobic violence is quelled as quickly as possible, Police Minister Nathi Mthethwa said on Thursday.

"Our security agencies are prepared to effectively deal with violence against anyone, including foreign nationals," Mthethwa said at a press conference in Pretoria on xenophobic violence.

"We continue to monitor all and any threats. Should anything be found to be credible, measures will be implemented immediately to prevent any outbreak of violence."

Mthethwa said that an investigation had found that the scores of foreigners leaving Cape Town in the past few days were not going out of fear of xenophobic violence, but because they were seasonal workers.

"The people who planted this in the media did no investigation whatsoever," he said.

"We will resist this hysteria. We investigated this issue and the first thing we got is that we are dealing with seasonal workers."

Deputy Home Affairs Minister Malusi Gigaba said that his department was taking the rumours of xenophobic violence seriously.

"These rumours run the risk of eroding the victory we scored with the World Cup," he said. "We will not allow that." He said that South Africa's ports of entry were extremely busy with foreigners leaving. He said that most of the people leaving were from Lesotho and Southern African Development Community countries, but this had nothing to do with xenophobic fears.

"There are no reports of people leaving out of fear for xenophobic violence," he said.

State Security Minister Siyabonga Cwele said that a small group of instigators were fuelling the rumours of xenophobic violence.

"Those who are planning on breaking our law, will be dealt with by the law enforcement agencies." Mthethwa said xenophobia had largely been caused by local business owners who felt that the prices of their goods were being undercut by foreigners.

He said thatthe government had to look at gaps in legislation to ensure that all traders were treated "fairly".

"Traders by-laws need to be enacted as a matter of urgency for there to be a proper and fair environment for competition," he said.

Mthethwa said that there had been a proliferation of businesses owned by foreign nationals in the townships and informal settlements across all provinces.

"Furthermore, there is a sharp increase in anti foreigner sentiment spreading from metropolitan cities and surrounding townships to smaller towns and rural areas across South Africa."

Mthethwa said tensions between owners of businesses owned by locals and foreign nationals had spawned an ugly element of "criminal involvement, exploitation and manipulation".

"In many instances criminals, aided and abetted by locals, particularly the youth are given a licence by some locals to loot and pillage foreign businesses."

The perception among foreign shop owners is that law enforcement agencies fail to protect, he said.

"Thus, as a response, foreign owned business owners resort to defensive measures to prevent looting of their shops."

On Thursday evening, the defence department clarified reports the Army had been deployed to prevent possible xenophobic attacks.

"The force was not deployed for xenophobia. As part of World Cup measures, they were deployed with the police as part of the safety and security plan around stadiums," spokesman Siphiwe Dlamini said.

"They conducted high-density operations to help ensure that the host cities and surrounding areas remain crime free."

Media reports linking this to xenophobia were "unfounded".