HANGZHOU, April 29 -- A crime ring of nearly 500 suspects who allegedly sold fake base stations for telecom fraud has been busted in east China's Zhejiang Province, according to local police.

It was the largest case of this kind to be cracked since February, when the Ministry of Public Security launched a campaign to target crimes involving fake telecommunication base stations, said Luo Enbiao, a police officer at the Zhejiang provincial bureau of public security on Monday.

After a month-long investigation, local police busted the gang, whose members were scattered across 29 provinces and municipalities, dealing a heavy blow to telecom spam fraud, Luo said.

In mid-April, more than 90 suspects were caught at a location in Hangzhou City, where 113 fake base stations and 2,120 spare parts worth nearly 10 million yuan were seized, Luo said.

Luo said that fake base stations can be easily assembled with a computer, an emitter, an antenna, a phone, a storage battery and a power adapter. The equipment sends out a high power signal which forces all mobile users in an area to disconnect from their legitimate base stations and instead receive messages from the fake station.

These spam messages are often sent from fake phone numbers and disguised as communications from judicial or administrative enforcers or customer service departments of telecom operators and banks.

Official statistics showed that Chinese mobile users received 300 billion SMS spam messages spreading false advertisements and fraudulent information last year.

Since the Ministry of Public Security tightened its crackdown on similar crimes in February, police have detained a total of 1,530 suspects and closed 24 production sites for illegal base station equipment by late March.