Updated

A video purportedly from Al Qaeda's chief of operations in Saudi Arabia (search) vowed to avenge the death of Muslims in Iraq and Afghanistan by expelling Americans from the Arabian Peninsula (search).

The video, posted on an Islamic Web site viewed in Dubai on Thursday, shows a masked man identified in a subtitle as Abdulaziz al-Moqrin (search) leaning on a semiautomatic rifle and with a rocket-propelled grenade launcher on his shoulder.

In the background, superimposed text reads: "Get the infidels out of the Arab Peninsula."

"You Americans, you dared to implant your bases in the Arabian Peninsula. ... You dared to hit Muslims in Afghanistan (search) and Iraq (search) from [bases in] the country of the two sanctuaries [Saudi Arabia]," the speaker says in Arabic in the 12-minute video.

"For what you have done, we will be following you. So watch out as you will see nothing from now on but our attacks as the real battle has just started," he says.

The Arabian Peninsula includes Saudi Arabia, Yemen (search), Oman and a number of important U.S. allies -- the United Arab Emirates (search), Qatar (search) and Bahrain. Qatar was the site of the U.S. headquarters during the Iraq war, and Bahrain is home to the U.S. Navy's Fifth Fleet.

It was not possible to verify the video's authenticity, but the speaker used language similar to past statements attributed to Al Qaeda (search). It appeared on a Web site that posts Sawt al-Jihad, a periodical of Al Qaeda ideology that carries news and statements relating to the terror network's operations in Saudi Arabia.

U.S. and Saudi officials believe al-Moqrin is Al Qaeda's top figure in Saudi Arabia and masterminded the Nov. 8 bombing of a Riyadh housing compound that killed 17 people, most of them Arabs and Muslims working in Saudi Arabia.