TEGUCIGALPA, Jan 15 (Reuters) - Hundreds of Hondurans and Nicaraguans on Saturday reached the Guatemalan border but were prevented from crossing by Guatemalan security forces, the first such U.S.-bound migrant caravan to be formed this year in Central America. Some migrants at the Izabel border crossing in Guatemala threw objects at Guatemalan security forces, who pushed them back with riot shields, according to a video shared by Guatemalan authorities. The caravan set off days before leftist President-elect Xiomara Castro takes office in Honduras on Jan. 27. She has vowed to revive the economy and combat corruption that stokes waves of mass migration to the United States. Earlier in the day, the migrants, mostly young people carrying backpacks on their shoulders and women with children, left a bus terminal in the northern city of San Pedro Sula for the Honduran border post of Corinto, across from Izabel. Some were pushing children in baby carriages. "There is no work," said Pablo Mendez, a Honduran carrying his 2-year-old daughter in his arms. "That is why people are leaving in this caravan." Reuters video footage showed large groups of hundreds of people walking across San Pedro Sula, with many crossing busy highways on foot. Another group had set off in the dark early in the morning. Guatemalan authorities said about 100 people crossed into Guatemala at unauthorized border crossings, and later added that some 36 people have been returned to Honduras. Previously, Honduran police have formed roadblocks to prevent many such caravans from reaching the border crossing. Guatemalan security forces have also clashed with migrant groups when they tried to force their way across without documents. The first caravan of the year comes after deep economic hardship and poverty that plagues 62% of the Honduran population, made worse by the coronavirus pandemic and two back-to-back hurricanes in 2020 that hobbled the economy. In Nicaragua, political crackdowns by President Daniel Ortega"s government before and after the Nov. 7 presidential elections have led to a surge in migration. Euclides Mendes, a Nicaraguan migrant, said the size of the caravan gave him hope that the treacherous journey would be safe. "It"s true that we"re going to walk a lot, but we"re going, and the important thing is to get to the finish line," Mendes added.