Following a two-month investigation, police have arrested 20 foreigners they believe were responsible for 20 thefts in the city and neighboring Jiangsu and Zhejiang provinces, the Shanghai Public Security Bureau said yesterday.

The bureau said the 20 suspects were divided into four gangs, but they all used the same simple tricks to grab money from their victims and flee. Police would not say what country, or countries, the suspects are from, nor would provide their names and ages, or say how much money they had stolen.

Police did say the suspects were divided into groups of three to five and they targeted supermarkets, roadside shops and gas stations.

Some gang members would distract the victims' attention by inventing various excuses while another gang member would steal money from cash registers or even snatch cash from the victim's hand.

"Usually they asked to exchange a 100-yuan (US$12) note for small change or for another note of the same value," said Fang Jie, a bureau official.

On several occasions, the suspects tried to change banknotes for bills with a certain number or letter in their serial number, she said.

Investigators claim the foreign thieves are very skillful, and could make off with cash before the victim noticed anything was wrong. City police first heard about the gang from a couple who runs a small grocery store near an expressway in Songjiang District.

One day in April several foreigners visited the shop and bought several bottles of juice. They then asked to change a couple of 100 yuan notes for bills with a serial number that started with the letter "A." To find such a note, the store owners led the foreigners into their bedroom and took a large sum of money from their safe.

"One of them snatched the cash, shuffled through it quickly and then returned the money to me," said the husband surnamed Zhao.

"They immediately left the scene in a Santana sedan waiting outside our store and later we found more than 4,000 yuan was missing," he recalled.

A similar trick occurred at a supermarket in Pudong New Area when the thieves asked the cashier for a 50-yuan note with a serial number that began with an "8."

(Shanghai Daily June 21, 2005)