Some 37 Africans, mostly refugees from Darfur, were arrested Friday in the Sinai Peninsula by Egyptian authorities who said they were attempting to cross illegally into Israel. The African migrants, four from Congo, five from Eritrea, and 24 Sudanese refugees mostly from the war-torn western Darfur region, were arrested at the Mubarak Asslam Bridge located on the eastern side of the Sinai, an Egyptian security official said. The official said another three Sudanese, and woman from Ivory Coast, were separately arrested Friday near the Israeli border. Speaking on condition of anonymity because he was not authorized talk to the media, the official said extra checkpoints had been installed in the Sinai to prevent the flow of illegal migrants from approaching the Egyptian-Israeli borders. Dozens of Sudanese refugees and other African migrants have been detained over the past few days for trying to cross into Israel from various points along Sinai peninsula. Many Sudanese find life difficult in Egypt, a country that struggles to provide jobs and social services for a growing refugee population. Egyptian riot police violently cleared a Sudanese refugee encampment in central Cairo in 2005, killing nearly 30 people. Israel says that about 2,800 people, including 1,160 Sudanese, have crossed illegally from Egypt through its porous Sinai desert border with Israel in recent years.