Consignments of a banned party drug called Yaba, weighing around 40kg and worth over Rs 11 crore, were seized from multiple pockets in Calcutta over the past fortnight.

The latest seizure, in the Maidan area on Saturday night, led to the arrest of four men, including a gram panchayat pradhan from Kaliachak in Malda district, police officers said.

“The seizure of such a large quantity of Yaba in such short time points at the increasing demand of the party drug in Calcutta,” an officer said.

“Yaba is a synthetic drug, which acts as a stimulant and affects the nervous system. It’s very popular among young people.”

Officers of the Special Task Force of the city police, which has made all the seizures, said a consignment of Yaba was found concealed in the front and rear door panels of a Nissan Sunny and a Maruti Swift Dzire, which were intercepted near Syed Baba Mazar in the Maidan area on Saturday night.

Of the four arrested, two are alleged drug peddlers from Manipur. The police suspect the accused were part of a large drug cartel.

“Around 1.2 lakh Yaba tablets, worth Rs 3.6 crore, were seized from the two cars. This was the largest haul in the past fortnight. Also, Rs 4 lakh was seized from the accused. They failed to explain why they were carrying the cash,” an officer said.

Yaba is a combination of methamphetamine and caffeine and has a hypnotic effect on users, an officer of the narcotics department said.

“It is very popular among young people because of its ‘happy’ effects. The drug is available in small, round, colourful tablets. It is cheaper than heroine or brown sugar,” the officer said.

Sleuths said Yaba and other party drugs were mostly manufactured in Myanmar and smuggled into the north-east.

“Usually, smugglers use Assam and Tripura as transit before entering Murshidabad and North 24-Parganas, from where the drugs are smuggled to Bangladesh. Yaba has a huge market in Bangladesh. It is evident a large quantity is entering Calcutta as well,” a senior officer of the city police said.