Ben Venzke, the head of IntelCenter, a US group that monitors and analyses al-Qaeda's messages, said it was not the first time As-Sahab has released videos designed for cell phones.

He said the group has been releasing them for years, but that between September and December, a few video messages did not come with versions for cell phones.

"They might just be filling in some of the gaps, or just trying to release some that had come out before," Venzke told The Associated Press.

In a written message introducing the new cell phone videos, al-Zawahiri, the deputy leader of al-Qaeda, asked followers to spread the group's messages.

He said: "I asked God for the men of jihadi media to spread the message of Islam and monotheism to the world and spread real awareness to the people of the nations."

Video sharing

Videos playable on cell phones are increasingly popular in the Middle East and Asia. The files are transferred from phone to phone using Bluetooth or infrared wireless technology.

Clips showing the execution of Saddam Hussein, Iraq's former leader, in December 2006 showed up on cell phones soon after his death.

In Egypt, images showing police brutality have been passed around via cell phones including one video that showed an arrested bus driver being sodomised with a stick by police in late 2006.

Video and audio tapes from al-Qaeda and other affiliated groups are available online, but require a computer and a fast internet connection to download, which is not always available.

Al-Qaeda has been growing more sophisticated in targeting international audiences. Videos are always subtitled in English, and messages this year from bin Laden and al-Zawahiri focusing on Pakistan and Afghanistan have been dubbed in the local languages, Urdu and Pashtu.