The US military plans to set up mobile phone antennas in southern Afghanistan to replace towers that have been shut down by Taliban militants, a US official said on Wednesday.

The mobile phone antennas will be set up at military bases across the south to counter the Taliban, which has blown up or forced the closure of most cellular phone antennas in Kandahar and Helmand provinces, the official said.

To provide a signal for Afghans, antennas will be set up on trucks and even balloons or unmanned drone aircraft, the military official, who spoke on condition of anonymity, told reporters.

Taliban militants regularly demand mobile phone companies switch off their networks or else have their towers destroyed, the official said.

The Taliban fear NATO-led forces can track their forces through phone signals and have ordered some phone companies to shut down service at night fall, when coalition troops often launch operations against the insurgents.

US military officers previously spoke about guarding mobile phone towers but have decided to set up new antennas at NATO forward operating bases instead.

The US military did not plan on entering into the mobile phone business and would merely be providing a signal that local companies could use, in cooperation with the central government in Kabul, the official said.

Mobile phones were crucial to helping revive commerce and communications in an area without landline telephones and regular mail, the official said.

"The main benefit will be to de-isolate people," he said.

But he acknowledged there was also a military advantage, as Taliban fighters would find it difficult to resist the temptation to use their mobile phones, giving away their position.

The move was part of a broader effort by the top NATO commander in Afghanistan, General Stanley McChrystal, to step up the "information war" against the Taliban, as both sides vie to win the trust of the population.

The insurgents have sought to sow distrust of foreign troops in radio broadcasts and intimidate opponents, delivering "night letters" to villages with warnings of retribution and distributing video of bombings.