Acting on a tip-off, members of the Sylhet 46 BGB, led by naik subedar Md Suruj Mia, took positions behind the Tamabil land port in Gowainghat upazila on Monday night.
The Nigerian national allegedly crossed over to Bangladesh illegally from India when a storm started around 9.30pm on Monday.
Sensing the presence of BGB, he tried to flee. But the BGB personnel nabbed him after a brief chase.
The process of handing him over to the Gowainghat police was underway, BGB sources said.