A large group of mostly Honduran migrants has crossed Guatemala and is entering Mexico in an effort to reach the United States. U.S. President Donald Trump has warned the group not to seek to cross the U.S.-Mexico border. On Sunday, the group some are calling a caravan, arrived at the Mexican border city of Tapachula and set up small camps under heavy rain. People in the caravan walked for hours from the Guatemalan border. They did not listen to police offers to take buses to a shelter because they were afraid they would be expelled from the country. The migrants have continued to walk despite warnings from Mexico. The government has said the migrants will be expelled if they cannot justify seeking asylum in Mexico. On Sunday, Trump said on Twitter that “full efforts are being made to stop” the caravan. He said migrants must ask for asylum in Mexico before seeking entry into the U.S. In southern Mexico, police with riot equipment followed the large group but did not try to stop it.