Police on Tuesday morning seized 635 bottles of phensedyl syrup from an ambulance in Aditmari upazila of Lalmonirhat district.
Aditmari Police Station sub-inspector Joynal Abedin said police searched an ambulance in Borabari area which came from Cumilla and recovered 635 bottles of the cough syrup.
They also detained the ambulance's driver Abdur Razzak, 41, and Liton Mia, 35, an alleged drug dealer, during the seizure, he added.
The police station officer in-charge Moktarul Islam said detained Liton is accused in four cases in Cumilla.