The commander of the Islamic Revolution Guard Corps has unveiled a handheld device that he said could identify people infected with the coronavirus within 100m (330ft), Tasnim news agency reports.

"The basis of this device is to create a magnetic field based on a bipolar virus inside the device, so its antenna can focus on any place within a 100m diameter that is infected by the virus, and identify the infected place in five seconds," Maj-Gen Hossein Salami was quoted as saying.

He added that its accuracy was "80%”, but provided no evidence.

Experts say the only reliable way to test for Covid-19 currently is by taking a swab of the nose or throat, which is sent off to a lab to look for signs of the virus’s genetic material.