MANILA, Philippines?The National Telecommunications Commission is considering a ban on the importation of electronic signal jamming devices that officials say can be used to sabotage the 2010 automated polls.

NTC said Monday it neither knew of nor authorized any shipment of 5,000 "jammers" which, according to the Commission on Elections, have entered the country.

A draft NTC memorandum order obtained by the INQUIRER on Monday showed the NTC's plan to ban the importation or sale of signal jamming devices in the country.

"Any person, natural or juridical, importing, selling and/or using GSM (Global System for Mobile communication) jamming devices shall be dealt with in accordance with law," the NTC draft said.

GSM jamming devices are used to prevent the use of GSM phones. Generally, these devices should not be used, the NTC said.

But the regulator said in places like churches, auditoriums and prison facilities, jamming devices have very useful applications, NTC Common Carriers Authorization Division Director Edgardo V. Cabarios said.

Jamming devices can be used in churches and auditoriums to minimize noise coming from ringing mobile phones. In prison cells, meanwhile, these devices can be used to curb illegal activities that use mobile phones, he added.

But in some cases, the official said jamming devices are used to play practical jokes on people using their mobile phones.

Reacting to the Comelec's statement on Monday revealing the entry of about 5,000 jammers into the country, Cabarios said the regulator had approved no such shipment.

"All radio transmitting devices need NTC permits before being brought in to the country. To my knowledge, the NTC has not approved any shipment of signal jammers," Cabarios said.

He said the NTC can start an investigation on the matter, but finding these devices will be difficult.

"These are hard to detect because they can be really small," Cabarios said.

The official admitted the possibility that jamming devices can be used to sabotage the upcoming elections by disrupting the transmission of data from polling precincts.

"But now everyone knows about this so the Comelec should be able to prepare their systems properly," Cabarios said.