GENEVA — The U.N.’s migration agency has released a survey of migrants in a caravan heading toward the United States in which nearly half of respondents said they are fleeing violence or insecurity.

The International Organization for Migration questioned 286 people in a caravan of about 1,700 people who left El Salvador’s capital on Oct. 31. IOM said it was one of several caravans crossing into Mexico.

Nearly four-fifths of respondents said they were seeking a better life in the U.S. About 45 percent said they were fleeing violence or insecurity.