Britain's Foreign Secretary Boris Johnson stands in front of St Basil's Cathedral during a visit to Red Square, in Moscow, Russia December 22, 2017. REUTERS/Stefan Rousseau/Pool

(Reuters) - Foreign secretary Boris Johnson on Monday called for Iran to engage in meaningful debate about issues raised by protesters which he said were “legitimate and important”, as the worst wave of unrest in almost a decade in the Middle Eastern country continued.

Johnson called for freedom of expression and the right to demonstrate peacefully to be respected, after street protests continued for a fifth day and with 13 people reported to have been killed on Monday.

“The UK is watching events in Iran closely. We believe that there should be meaningful debate about the legitimate and important issues the protesters are raising and we look to the Iranian authorities to permit this,” he said in a post on Facebook.