Musina - South African police in Limpopo on Thursday continued to keep an eye on the border town of Musina and the Beitbridge port of entry, even though violent protests have waned.
Protests erupted around the border area on Friday after Zimbabwe imposed a ban on basic food imports and other commodities from South Africa.
Cross-border traders blocked traffic on the South African side.
A building was torched on the Zimbabwean side of the border.
Zimbabweans also stayed at home on Wednesday and foreign banks and most businesses in the capital shut down, in one of the biggest protests against high unemployment, an acute cash shortage and corruption for nearly a decade.
Provincial police spokeswoman Colonel Ronel Otto on Thursday told African News Agency (ANA) that roadblocks and searches would continue near Beitbridge.
“The roadblock is to make sure that there are no incidents of violence and prevent masses of people from going to the border because we heard there are intentions of blocking the border,” said Otto.
Police are searching vehicles going to the border, checking that passengers have passports.
Those who failed to produce relevant documentation were being prevented from crossing the border.
The International Cross-Border Traders Association and local business formations in Musina said the ban imposed by Zimbabwe was hurting their members.
On Thursday the situation seemed to be returning to normal, but campaigners against the ban vowed to continue to pressure Zimbabwe's 92-year-old President Robert Mugabe and his embattled government to lift restrictions on imports the ban on imports of basic food.
Musina is one of several towns in the vicinity that benefited from the collapse of Zimbabwe's economy.
The unrest in the northern neighbour has resulted in a significant drop in business in Musina.
Restaurant cashier Dzulani Mbavhalelo said: “There is nothing that we are doing now, and it does not look like we will have jobs if the banning of imports continue.”
Some cross border traders were now risking life and limb by smuggling goods across the crocodile infested Limpopo River into Zimbabwe. They are also at the mercy of marauding criminal gangs.
Meanwhile, about 20 people working at a tourist resort, Elephant Walk, in Victoria Falls have been arrested, apparently in connection with growing unrest in Zimbabwe.
Well-known Zimbabwean wildlife artist Larry Norton was reportedly among those picked up on Wednesday by police in Victoria falls, Zimbabwe's premier tourist attraction.
Lawyers in Zimbabwe's second largest city, Bulawayo, say they are seeking the release of about 18 residents of Victoria Falls, some of whom were employed by the wildlife adventure company, Elephant-Walk.
A relative of one of those that were arrested, who asked not to be named, said “the lawyers are speaking with the police today. We don't know why they were arrested.”
The arrests are believed to be in connection with a social media campaign, This Flag, which asked all Zimbabweans to go on strike on Wednesday as a protest against the government, which failed to pay many civil servants’ June salaries.
Evan Mawarire, a pastor whose social media movement #ThisFlag organised the “stay-away”, demanded that President Robert Mugabe fire corrupt cabinet ministers and scrap plans to introduce local bank notes or face a two-day shut-down next week.
Wednesday's protest followed violent clashes between taxi drivers and police on Monday that led to the arrest of 95 people. It also coincided with a strike by doctors, teachers and nurses whose salaries had been delayed.
A devastating drought has compounded economic hardships including high joblessness while an acute cash shortage has angered Zimbabwe's citizens.
The 39-year-old Mawarire started the #ThisFlag campaign in April to protest against corruption, injustice and poverty.
The campaign has attracted thousands of followers who have been speaking out against government excesses. Wednesday's protest was organised via Twitter, Facebook and WhatsApp.
Mawarire's campaign includes a series of demands: for Mugabe to fire and prosecute “known” corrupt ministers, for government salaries to be paid on time and for police to remove roadblocks which most people say are posts for bribe taking officers.
“The ball is in your court,” Mawarire said on his Facebook page. We are ready to close down again and this time we will add another day, Wednesday and Thursday. We are not playing and we ask you to take us seriously.”
Mugabe's spokesman, George Charamba, was not available to comment.
State telecoms regulator POTRAZ said in a statement it would arrest people sending “subversive” messages that cause unrest.
Mugabe, who has held power since Zimbabwe gained independence from Britain in 1980, was attending a scheduled meeting on Wednesday of his party ZANU-PF's politburo, the party's top executive organ. Party spokesman Simon Khaya-Moyo declined to say whether ZANU-PF would discuss the protests.
In the volatile township of Mufakose, to the west of Harare, hundreds of youths barricaded roads to keep people from going to work.
More than 40 people were arrested across Zimbabwe for blocking roads and disturbing the peace, said Charity Charamba, a police spokeswoman.
There was no need to call out the military, Charamba said.
“The military is not there because in our assessment, for now, the situation has not deteriorated (enough) to warrant the presence of the military,” Charamba told reporters.
Zimbabwe last witnessed such a protest in April 2007.
Reuters and ANA