The Rapid Action Battalion arrested four more suspected drug peddlers from Dhaka's Tejgaon industrial area on Saturday night.
Lysergic acid diethylamide (LSD) and a new drug Dimethyl Tryptamine (DMT) were recovered from their possession, said Rab officials.
The arrestees are Syed Moinuddin, Abraham Zunayed Taher, Swapnil Hossain, and Simiyon Khandaker.
All the arrestees are from rich family background. They studied in United Kingdom, Thailand and two private universities in Bangladesh.
RAB recovered 40 LSD blotting papers, 600mg of DMT and 82gm of cannabis smuggled from USA from their possession, Khandaker Saiful Alam, commanding officer of Rab-2, said at a press briefing on Sunday.
The arrestees used to smuggle the drugs from abroad through postal services, the RAB officer said.
"We have no previous incident of seizure of DMT, another hallucinogenic drug like LSD, in the country," said Saiful, adding that the relatively new drug can be produced in chemical labs.
The arrestees, during preliminary interrogation, have confessed that they collected 600mg of DMT at around Tk20,000, he added.
After completing O-level from an English medium school in Uttara, Moinuddin went to India where he completed A-level. Later, he moved to Thailand to study BBA in 2015 and there he became addicted to LSD and DMT.
After returning from abroad, Moinuddin used to collect the drugs through postal service and continued abusing the drugs and started selling to others, the RAB officer said.
Taher went to Malaysia after completing O-level and stayed there till 2016. Later, he went to UK where he got addicted to LSD and DMT. Returning home in 2020, he started selling the drugs in the country, said Saiful, adding that Swapnil and Simiyon, two students of private university, are their accomplices in drug peddling.
Earlier, five youths, all students of private universities, were arrested from different parts of the capital by the Dhaka Metropolitan Police's Motijheel division on 30 May.
On 27 May, three students were arrested on charges of peddling hallucinogenic drug LSD in the capital, following Dhaka University student Hafizur Rahman's death.