A migrant, who was part of a caravan of thousands from Central America trying to reach the United States, crawling through a gap in the border wall to cross illegally from Mexico's Tijuana to the US on Thursday.

On the same day, The Washington Post reported that a Guatemalan girl, seven, one of many migrants who sneaked into New Mexico, in the US, died of "dehydration and shock" after being detained by US border police.

A US Customs and Border Protection statement said she "reportedly had not eaten or consumed water for several days", and went into cardiac arrest.

US President Donald Trump has made hardline immigration policies a central plank of his presidency, drawing fire from critics who accuse him of demonising migrants for political gain.

Much attention has been focused on caravans of thousands of Central Americans who have made their way to Tijuana, just south from San Diego, California, in a challenge to Mr Trump, who has criticised them as posing an "invasion".