Law enforcers are concerned about a new variety of yaba, because unlike the conventional pills, these are yellow, odourless and large enough to be mistaken for prescription drugs.

The usual "WY" inscribed methamphetamine pill, frequently seized by law enforcers, is mostly red or green and may sometimes smell like vanilla.

Investigators said for years, they have seen hauls of the 0.10 gram pills Rab officers in Chittagong said traffickers, when stopped by law enforcers, sometimes tried to pass the hauls as cattle-fattening medications.mainly smuggled into the country from Myanmar on boats and other transports.

Since a number of prescription drugs and even vitamin supplements on the market have similar appearances, law enforcers are worried that drug traffickers and users would sometimes evade detection. They seized a large drugs haul including 1,000 yellow pills on October 20 in the city's Barisal Colony area. But no one was arrested.

Police officers said, a total of 35,000 yellow yaba pills were seized by Border Guard of Bangladesh (BGB) and Rab on August 28 and September 16 in Akbar Shah and Sadarghat areas respectively. Two suspects arrested at Sadarghat are being interrogated.

BGB Director (operation) Lt Col Nasiruddin Ekram of South East Region said, "It is a new version of yaba. It is sold at higher prices than the older ones."

Squadron Leader Shafayat Jamil Fahim of Rab-7, who seized the haul in Sadarghat, said, "We have learnt that the yellow yaba are being smuggled to Bangladesh from India and we have confirmed that the pills contain methamphetamine.

"They have come up with this to dodge law enforcers. They pass these as cow-fattening tablets."

He added that the pills were trafficked through borders in Comilla and Shatkhira.

"Yaba used to be smuggled into Chittagong from Myanmar. But this time, we found that the consignments of yellow pills were brought here from Comilla."

Rab-7 Assistant Director (media) Mimtanur Rahman said, "After the seizure, our officers became a little puzzled when die suspects claimed that those were cow-fattening pills. But we found out the truth after examining the pills at our central lab in Dhaka."

After a case was filed with Sadarghat police station in this regard, police sent five pills to Criminal Investigation Department's lab for tests.

The test report, issued by Kaisar Rahman, chemical examiner at Chittagong CID, said there was methamphetamine in the pills each weighing 0.19 gram.

Officer-in-Charge Alamgir Hossen of Akbar Shah Police Station said, "After BGB's seizure, we also sent a few pills to the CID lab only to confirm what we already knew."

Shamim Ahmed, deputy director of Department of Narcotics Control in Chittagong (metro), said the yellow pills were not seen in the country before and they were trying to find out more about them.

Detectives also said they were investigating the source of the pills.