Sudan's president Omar al-Bashir on Sunday told police to abstain from using excessive force against anti-government demonstrators as the UN called for a probe into deaths during the violent protests.At least 19 people have been killed since December 19 during protests sparked by Khartoum's decision to hike the price of bread, according to the government. Rights group Amnesty International says 37 people have died.On Sunday, Bashir met top police officers in Khartoum and instructed them to refrain from using excessive force against demonstrators."We want to maintain security and we want the police to do that by using less force," Bashir, dressed in a blue police uniform, said.Protesters have rallied after the government raised the price of a loaf of bread from one Sudanese pound to three (from about two to six US cents).Sudan is facing an acute foreign exchange crisis and soaring inflation despite Washington lifting an economic embargo in October 2017.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook. Inflation is running at 70% and the Sudanese pound has plunged in value, while shortages of bread and fuel have regularly hit several cities."We admit that we have economic problems... but they can't be solved by destructions, lootings, and thefts," Bashir said, referring to buildings and ruling offices torched by protesters in several cities during the demonstrations."We don't want our country to go the way other countries in the region have gone," he said."We will not allow our people to be refugees. If this happens where can we go in this region?"UN Secretary-General Antonio Guterres appealed "for calm and restraint" and called on "the authorities to conduct a thorough investigation into the deaths and violence", a UN spokesman said in a statement on Friday.The UN chief is "following with concern" developments in Sudan and "emphasises the need to safeguard freedom of expression and peaceful assembly", the spokesperson added.