Lieutenant Colonel Sheikh Mohammad Badrudoza, commanding officer of Nilphamari-56 BGB Battalion, confirmed the matter early Thursday.
According to the BGB, the incident took place around 4.15am near sub-pillar No. 10 of main pillar 757 in Haribhanga Union under the jurisdiction of Nilphamari-56 BGB Battalion.
A petrol team of the BGB arrested those illegal infiltrators from 2.5 kilometers inside Bangladesh land from the border pillar of Barobari under Haribasha, the BGB official said.
Of the 21 individuals, six are women, two are men, and 13 are children, reports BSS.
BGB is preparing to file a case under the Passport Act with Panchagarh Sadar Police Station, he added.