PESHAWAR: Unknown militants set off an explosive device early on Sunday morning damaging four CD shops in Mattani area in the outskirts of Peshawar near Main Kohat road and the bordering area with Darra Adamkhel, DawnNews reported.

A pamphlet was found at the site of explosion which warned of more attacks against those engaged in the 'un-Islamic' businesses.

A local trader in the area talking to Dawn.com confirmed that a pamphlet was received in the market according to which,  all 'immoral' businesses would face share the same fate as the targeted CD shop.

A local police official told Dawn.com that one kilogram of explosive material was used in the blast adding that no one was harmed in the attack.

Earlier this month, shop keepers in Peshawar discontinued the sale of mobile phone SD memory, USB flash memory and other media after the Pakistani Taliban had threatened to blow up mobile phone markets for selling 'shameless' video clips, ringtones and accessories.

The Tehrik-i-Taliban Pakistan (TTP) and other militant organisations have also warned in the past of attacks against those selling viagra, obcene films and also against those running net-cafes and CD shops.