The number of migrant families with children crossing the southern border has nearly tripled in the past two months, according to Customs and Border Protection data obtained by NBC News, feeding concern among some senior administration officials about a potential uptick in overall migrant crossings.
Earlier this week, more than 2,230 migrants were crossing the border daily on average, up from 790 in early June. While single adults are still the largest demographic seen at the border, families are the fastest-growing demographic of undocumented border crossers, according to the data. Most of the migrants are from northern Central America and Mexico, according to the data.
Three senior Department of Homeland Security officials who spoke on the condition of anonymity say they are closely watching the number of families coming because of growing concern the numbers could soon spike and send border numbers back to near record highs.
Immigrant advocates say more families are crossing to escape poverty and violence in their home countries, as well as to escape cartels and extreme heat they encounter while waiting to cross in Mexico.
Get top local stories in San Diego delivered to you every morning. Sign up for NBC San Diego's News Headlines newsletter.
Read the full story on NBCNews.com here.