(Reuters) - Sudanese security forces used tear gas on Sunday to break up a crowd of hundreds of people، mostly young women، demonstrating against the detention of women arrested at previous protests، witnesses said. The protesters chanted: “Long live the struggle of Sudanese women”، and “Down، that’s it”، one of the main slogans calling for the fall of President Omar al-Bashir during protests that have swept Sudan since Dec. 19. Security forces at the protest، in Omdurman، Sudan’s second-largest city which faces the capital Khartoum on the other side of the River Nile، were seen arresting young women and taking them away in at least four pick-up trucks. The protesters were trying to march towards a large women’s prison before security forces moved in. The protests that have spread across Sudan were triggered by a worsening economic crisis and have built into the most sustained period of unrest since Bashir came to power three decades ago. Bashir and senior officials have adopted more conciliatory language about the demonstrations، including promises to release jailed protesters، but security forces have continued to break up rallies and arrest people. In Omdurman’s Wad Nubawi neighborhood on Sunday، protesters blocked a road، setting fire to branches and throwing stones before security forces fired tear gas to disperse them. Dozens of doctors also protested inside the state hospital in El-Obeid، the capital of North Kordofan state، about 360 km (220 miles) southwest of Khartoum، calling for Bashir to step down، witnesses said.