British Foreign Secretary Boris Johnson called on Monday for freedom of expression and right to demonstrate peacefully to be respected in Iran as anti-government protests in the country continued to rage. “The UK is watching events in Iran closely,” he said a post on Facebook. “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 added. Thirteen people have been killed in the demonstrations that began on Thursday. "We regret the loss of life that has occurred in the protests in Iran, and call on all concerned to refrain from violence and for international obligations on human rights to be observed," Johnson said. The rallies kicked off in Mashhad over Irans weak economy and a jump in food prices and have expanded to several cities, with some protesters chanting against the government and the supreme leader, Ali Khamenei. Hundreds of people have been arrested. On Sunday, Iran blocked access to Instagram and the popular messaging app Telegram used by activists to organize. US President Donald Trump, who has been tweeting in support of the protesters, continued into the New Year, describing Iran as "failing at every level despite the terrible deal made with them by the Obama Administration." "The great Iranian people have been repressed for many years," he wrote. "They are hungry for food & for freedom. Along with human rights, the wealth of Iran is being looted. TIME FOR CHANGE!"