A woman was allegedly gang-raped by four men at Karai Barishal Char in Chilmari upazila on Wednesday night.
Two suspected rapists were arrested the following day after the victim filed a case, Kurigram police chief Mehedul Karim said.
Police said they arrested prime accused Ranju and another man from their homes.
The victim came to the upazila to look for her niece on Wednesday night.
Ranju promised to help her and took her to a remote shoal where the accused and three others raped her, the officer said.