Crates of masks snatched from cargo planes on airport tarmacs. Countries paying triple the market price to outbid others. Accusations of “modern piracy” against governments trying to secure medical supplies for their own people.

As the United States and European Union countries compete to acquire scarce medical equipment to combat the coronavirus, another troubling divide is also emerging, with poorer countries losing out to wealthier ones in the global scrum for masks and testing materials.

Scientists in Africa and Latin America have been told by manufacturers that orders for vital testing kits cannot be filled for months, because the supply chain is in upheaval and almost everything they produce is going to America or Europe. All countries report steep price increases, from testing kits to masks.

The huge global demand for masks, alongside new distortions in the private market, has forced some developing countries to turn to UNICEF for help. Etleva Kadilli, who oversees supplies at the agency, said it was trying to buy 240 million masks to help 100 countries but so far had managed to source only around 28 million.