Education authorities in some cities are distributing mobile phone signal detectors to adult college entrance exam supervisors to try to prevent cheating.

Beijing, Hefei, the capital of Anhui Province, and Taiyuan, Shanxi Province, were among the first to use the device Saturday and Sunday.

No bigger than a cigarette packet, the detector can trace a mobile signal to the phone user within a radius of 30 meters. However, several Beijing newspapers said the detector turned out to be not sensitive enough to catch every text message usage.

Last year, more than 100 students were caught in Beijing's adult college entrance exam using mobile phones to receive test answers. This accounted for 40 percent of the total number of students caught cheating.

Earlier this year, the Ministry of Education banned exam candidates from carrying modern telecommunication devices into exam rooms. Anyone found cheating is banned from taking the test again.

The adult college entrance exam is a second chance for students who fail the national university entrance examination. Last year, about 4 million people took the exam in China.

(Shenzhen Daily October 18, 2004)