An increasing number of people from far-flung corners of the world quietly have tried to sneak into the United States among the hundreds of thousands of other, mostly Latin American migrants caught at the Mexican border in the last year, according to arrest data from the Department of Homeland Security.

The arrests of more than 8,000 people from India, China, Romania, Bangladesh and Nepal between October 2015 and the end of August is offering a new challenge to immigration agents tasked with fully identifying would-be immigrants and quickly deporting people caught crossing the border illegally.