TIJUANA, Mexico (CBSDFW.COM/AP) — At least 40,000 migrants who have reached the U.S. border with Mexico are on waiting lists for an initial attempt to seek asylum or are waiting for a court hearing in the U.S. after being sent back.

The figure — based on reporting by The Associated Press and Mexican government figures — represents a dramatic increase from the start of the year.

English-speaking Cameroonians fleeing atrocities of their French-speaking government helped push Tijuana’s asylum wait list to 10,000 on Sunday, up from 4,800 just three months earlier.

Turning Mexico into a waiting room for U.S. asylum seekers may be the Trump administration’s most forceful response yet to a surge of migrants seeking humanitarian protection, many of them Central American families.