A prolonged closure of the border would be costly not only to the mining sector but also to both economies more widely, and would be a fresh blow to investor sentiment towards Mozambique, where police fired tear gas at hundreds of opposition supporters converging on the capital Maputo on Thursday for the biggest demonstration yet against last month's disputed election.

Listen to this article 6 min Listen to this article 6 min The temporary closing of the Lebombo border crossing into Mozambique from South Africa, triggered by escalating protests over last month's disputed election, is a fresh setback to South African chrome producers and other miners who have been switching to the port of Maputo to export their bulky product in the face of Transnet's woes.

Reuters reported that fresh violence erupted around Maputo on Thursday morning, 7 November, as Mozambican police fired teargas at hundreds of opposition supporters gathering for a mass Day of Freedom demonstration - a signal that the unrest is far from over.

Even if the border closure is relatively brief, the fall-out from the election will likely remain an unwelcome political and security risk for companies that have come to rely increasingly on the port of Maputo. The ruling Frelimo Party, in power since Mozambique's independence from Portugal in 1975, has responded to the protests with violence and a throttling of internet access.

In a sign of the ripple effect from the border closure and the mounting unrest, South African logistics company Grindrod said on Thursday that it had suspended its port and terminal operations...