Image caption Taleban have started using modern technology to spread their influence among Afghan polulation

Taliban insurgents are making use of widely-available mobile phones in Afghanistan as a propaganda tool.

The group is sending video and text messages to deter the population from supporting the Afghan government or joining the security forces.

They also project their authority in the south and east by imposing night-time bans on mobile services.

Meanwhile, an increasing number of Afghans upload Taliban religious chants and ringtones as a kind of travel insurance to avoid intimidation in areas with a heavy insurgent presence.

The clips sent by the Taliban to subscribers include beheadings, real-life suicide bombings and roadside bomb explosions.

If they have problems with the Taleban in their areas they come in and upload Taleban chants Shop owner, Jalalabad

They are intended to warn the populace against supporting the authorities or joining the Afghan National Army or the police.

Images of civilian casualties and incidences of alleged disrespect to Afghans and Muslim beliefs by foreign forces are also being sent.

Danesh Karokhel, director of independent news agency Pajhwok Afghan News, told the US-funded RFE-RL radio website that the Taliban were using the videos to "spread terror" among the people.

"They want to scare people so they do not support the government. They threaten people. Whoever sees those kinds of videos will obviously be scared," he said.

Masts destroyed

While the US military surge a year ago was taking a big toll on the insurgents in the south, they retaliated by imposing a night-time ban on mobile phone services in the regions, including provincial capitals.

Your white tender body has been burnt by fire Oh martyr! Zarf, which oppressor has shot you? I tend to the wounds of your beautiful limbs and the dry tender lips and burnt wounds Taliban chant

This was not only to prevent the tracking and targeting of Taliban commanders and fighters by US forces, but also to demonstrate control in the regions.

Worried about psychological and other adverse impacts of the Taliban moves, President Hamid Karzai warned the mobile companies that their licences could be revoked if they caved in to Taliban orders.

But when the providers defied Taliban warnings, the group destroyed nearly three dozen transmission masts within a few weeks. The cost to the companies of repairing a tower is at least $200,000.

An increasing number of Afghans are uploading Taliban chants and ringtones to use them as travel insurance by pretending to be Taliban sympathisers.

When travelling in southeastern areas where the insurgents are strong, they delete from their phones any audio or video the Taliban might consider offensive or any evidence of links with the government or the coalition forces.

A report by leading Afghan channel Tolo TV late last year on Taliban chants showed that people go to extraordinary lengths to avoid insurgent intimidation.

Image caption Mobile phones enjoy great popularity in Afghanistan in the absence of a landline phone infrastructure

A video-shop owner in the eastern city of Jalalabad told the TV: "People choose these religious chants if they have problems with the Taliban in their areas. So they come in and upload Taliban chants."

Under Afghanistan's pre-2001 Taliban administration, music was deemed un-Islamic and shopkeepers were arrested for selling music tapes. Music was forbidden at weddings and musical instruments prohibited.

The Taliban recently launched a website for religious chants. The site also provides links to sermons, such as those in support of jihad, martyrdom, the veil and the ban on music.

The boom in mobile phone ownership is one of the major success stories of Afghanistan since the fall of the Taliban a decade ago.

There are over 17 million Sim card subscribers in the country, with four major service providers: Afghan Wireless Communication Company (AWCC), Roshan, Etisalat and MTN. Over 85% of Afghans have access to telecom services, according to Telecommunication Minister Amirzai Sangin, who says that the network should cover the whole country by 2014.

In the absence of a landline phone infrastructure in Afghanistan, mobile phone service disruption causes major problems for residents, government and businesses.

BBC Monitoringselects and translates news from radio, television, press, news agencies and the internet from 150 countries in more than 70 languages. It is based in Caversham, UK, and has several bureaux abroad.