An der US-mexikanischen Grenze wurden zuletzt 223 Asylsuchende aus Sub-Sahara-Afrika gezählt.
United States immigration agents are trying to work out why there has been a surge in the number of African asylum seekers crossing the border from Mexico.
These people are mostly from the DRC and Angola. They have all arrived in the past week and requested to go to Portland while their asylum cases are being reviewed.
From the southern US, some have been sent thousands of kilometres to a new arrivals centre in the northeast state of Maine.