The victims have been identified as Rahat Islam Palash, 30, and his nephew Fahim Onik, 23.
The incident occurred around 1:30 AM on the Kushtia-Jhenaidah highway, in front of Kushtia Zilla School, according to local police.
Mosharraf Hossain, Officer-in-Charge of Kushtia Model Police Station, stated that the motorcycle was entering the highway from a side road and was heading toward Chourhash when it was struck by a speeding private car coming from the Mojompur Gate area.
The force of the collision threw the two riders off the motorcycle, causing their immediate deaths. A third passenger, 23-year-old Tanvir Gani, was injured and is receiving treatment at the 250-bed General Hospital in Kushtia.