Clouds of the noxious gas could be seen wafting up from around the fence at the border, and one migrant picked up a canister and threw it back into US territory. US officials said the group had attacked agents with projectiles, but a Reuters witness did not see any migrants throwing rocks at US agents.
The US government's system for detaining migrants crossing the border is severely overtaxed. Authorities would not say how many children US Customs and Border Protection is now holding. But the country is seeing a sharp rise in families with children.
The Trump administration announced in June 2018 that it would open the temporary shelter for up to 360 migrant children in this isolated corner of the Texas desert. The facility has expanded into a detention camp holding thousands of teenagers
The group set out from El Salvador on November 18 and apparently crossed the river dividing Guatemala and Mexico on Tuesday. That is the same route the three larger caravans took after entering Mexico starting October 19.
The absence of the 463 parents, which U.S. government lawyers said was "under review," could impede government efforts to reunite separated families by Thursday, the deadline ordered by a federal judge.
The Justice Department on Friday filed a plan to reunify more than 2,500 children age 5 and older by a court-imposed deadline of July 26 using "truncated'' procedures to verify parentage and perform background checks, excluding DNA testing.