The addict-muggers, who normally operate on running buses, mostly target female passengers and those who take window seats.

These muggers prefer to snatch wristwatch, mobile phone and ornaments from unwary passengers as soon as the buses move from their designated stops.

Besides, several organised groups comprising 4 or 5 members are also active in mugging in the capital.

The drug addicts are active in several key bus stoppages, which generally remain crowded from morning till evening.

These bus stoppages include Gabtali, Mohakhali, Sayedabad, Farmgate, Maghbazar, Malibagh, Gulistan, Motijheel, Mirpur-10 `Gol Chakkar', Kazipara, Sheorapara, Agargaon, Sangsad crossing, Karwan Bazar, Bangla Motor and Shahbagh crossing.

A top-ranking official of Detective Branch of Police said that at least 50 organised groups of muggers were active in 29 vulnerable points in the capital a year ago.

Each of these 50 groups was posted at different turning points by rotation, he said, adding that the number of such groups of muggers has decreased due to repeated drives by law enforcing agencies.

"Instead of the organised groups, heroin addicts and juveniles from roadside slums are now active in snatching," the DB official said.

Witnesses said when a bus stops or slows down its pace, the addict-muggers pounce on passengers sitting beside the window or near the door. Most of the victims are those who wear gold necklace or chain, and carry mobile phone and wristwatch.

In many cases, female passengers receive injuries tearing their earlobes or choking and scratching their throats while snatchers try to snatch their earrings or necklace.

On a number of occasions, such incidents occurred in front of law-enforcers, yet they look on without taking any action, witnesses said.

"The problem is that neither the drivers can afford to stop, nor can the victims jump out to chase the snatchers," a victim explained.

There is an allegation that several organised groups of muggers operate in the city with the help of some corrupt policemen.

A police official of Tejgaon Police Station, however, denied the allegation saying, "We are very much serious to curb such kind of criminal activities."

He said most of the arrested snatchers were found to be heroin-addicts. Police cannot imprison the drug addicts as they show symptoms of sudden deterioration of their physical condition.

"We produce them before the court and they get bail and again return to mugging," he added.