Anti-government protests erupted in the Sudanese capital Khartoum and its twin city Omdurman after midday prayers Friday in continuation of weeks of rallies against a spike in prices and the rule of President Omar al-Bashir. Crowds chanting "freedom, peace, justice" demonstrated in two areas of Khartoum and in Omdurman just across the Nile, witnesses said. They were quickly confronted by volleys of tear gas from riot police. Friday’s protests appeared to have drawn more people than before and were more widespread. In previous weeks the protests began only after sundown. Organizers called for nationwide demonstrations over the next week demanding Bashir resign. North of Khartoum, demonstrators blocked the main road linking the capital to the Red Sea city of Port Sudan, witnesses said, without giving any further details. Three demonstrators were killed during protests on Thursday and Amnesty International accused security forces of chasing injured victims into the Omdurman hospital. Authorities said they had set up a commission to investigate the incident. Protests that first erupted on December 19 over a government decision to triple the price of bread have swiftly escalated into broader demonstrations widely seen as the biggest threat to Bashirs rule in his three decades in power. "We will launch a week of uprising with demonstrations in every Sudanese town and village," the Sudanese Professionals Association said. The group called for a major rally in Khartoum North on Sunday, to be followed by further demonstrations in the capital during the week. The association, which has mobilized its membership to keep up the momentum of the protests, has also called for a rally later on Friday in the eastern town of Atbara, where the demonstrations first began. At least 22 people have been killed during the protests, including two security personnel, according to the authorities. Rights groups have put the death toll much higher. Human Rights Watch said on Monday that at least 40 people had been killed, including children and medical staff. Analysts say the challenge now for organizers is to get protesters onto the street in numbers. “Right now, some of the opposition groups and trade unions are trying to mobilize more protests, and probably they are thinking of how to escalate," said Matt Ward, senior Africa analyst at Oxford Analytica, according to AFP. "But so far there hasnt been an escalation, they are persistent but they havent risen in intensity in a significant way." Although the immediate trigger for the protests was the price of bread, Sudan has been facing a mounting economic crisis over the past year, led by an acute shortage of foreign currency. Repeated shortages of food and fuel have been reported in several cities, including Khartoum, while the cost of food and medicine has more than doubled. Bashir and other officials have blamed Washington for Sudans economic woes. Washington imposed a trade embargo on Khartoum in 1997 that was lifted only in October 2017. It restricted Sudan from conducting international business and financial transactions. The foreign currency shortages began with the 2011 secession of South Sudan, which took with it the bulk of oil revenues. The president has remained defiant telling thousands of loyalists at a Khartoum rally on Wednesday that his government would not give in to economic pressure. "Those who tried to destroy Sudan... put conditions on us to solve our problems, I tell them that our dignity is more than the price of dollars," Bashir said. Human rights groups say more than 1,000 people have been arrested since the protests began, including opposition leaders, activists and journalists as well as demonstrators. The crackdown has drawn international criticism with Britain, Canada, Norway and the United States warning Khartoum that its actions would "have an impact" on its relations with their governments. Sudan has dismissed their concerns as "biased" and has insisted it is "committed to freedom of expression and peaceful demonstrations".