GUATEMALA CITY, Jan 17 (Reuters) - Guatemalan authorities said on Monday they have sent back more than 600 migrants who entered the country in a caravan that was bound for the United States. Guatemala"s foreign ministry said 622 people, mainly from Honduras and Nicaragua, entered through border posts with Honduras, with minors making up about a quarter of the group. The caravan left Honduras on Saturday but was largely broken up over the weekend. Video images showed Guatemalan police using riot shields to stop a large group of migrants from pushing forward. The authorities said some people made illegal crossings as well. The Guatemalan ministry said the migrants, who are mostly men, were returned to their nations or the country from which they entered Guatemala because they did not meet immigration or health requirements. Fifteen Cubans were returned to Honduras. Migrants elsewhere said they would press on with plans to cross Central America in a northward direction. "We can"t go on another day here ... I want to get to the United States," said a Nicaraguan man who planned to leave his country on Monday and asked not to be named. The U.S. government has sought help from Central American nations and Mexico to prevent large groups of people from heading north to the U.S. border. Several U.S.-bound caravans have left Central America in recent months as people from across Latin America and the Caribbean flee poverty and violence, but the groups have largely broken up during the difficult route. Guatemala"s consulate in the Mexican state of Veracruz on Monday said it was assisting close to 300 Guatemalans, including 55 unaccompanied minors, who were detained as they were being transported in a truck along with 65 people of other nationalities. The consulate said in a statement it would follow up with each Guatemalan after medical examinations so that "they can return to Guatemala soon."