A teenager drowned in the Turag River on Thursday night while fleeing an angry crowd after allegedly setting an empty bus on fire at Mirpur.
The deceased was identified as Sayyaf, 18. Another youth, Rudro Mohammad Nahian Amir Sani, 18, was detained at the scene, while a third suspect managed to escape, police said.
Shah Ali Police Station officials said the incident took place around 10:05 pm near the west side of Sohel Engineering Workshop at Uttar Nababerbagh.
DMP Deputy Commissioner (Media) Talebur Rahman said witnesses saw several youths pour kerosene from plastic bottles onto the parked bus, set it ablaze, and record the act on their mobile phones. Locals chased the perpetrators, catching one.
One suspect jumped into the nearby Turag River while trying to flee but drowned.
He was rescued in critical condition and rushed to Shaheed Suhrawardy Medical College Hospital, where doctors declared him dead.
Police have taken the detainees into custody and are searching for the third suspect. Legal proceedings over the arson are underway, the DC (Media) added.