The alleged al-Qaida statement, which appeared on an Islamic website Monday, warned of new attacks against "all compounds, bases and means of transportation," including airlines from the United States and other Western countries, which the statement said would be a direct target of coming operations.

The statement asked Muslims in Saudi Arabia to stay away from Americans and other Westerners to avoid becoming victims of the promised attacks.

However, a terror expert at the al-Ahram Center for Political and Strategic Studies in Cairo, Hala Mustafa, told VOA that she was not certain the statement came from al-Qaida. She and other terror experts have said it has not been the history of al-Qaida to announce attacks before they occur. Instead, they say, al-Qaida usually carries out attacks and then claims responsibility for them.

Terror experts in the region agree the purpose of such pronouncements is to instill fear in the public as part of a broader terror campaign. They say the goal is to make the public believe such groups are larger, more well organized and more powerful than they really are.

The threats against Western airlines operating in Saudi Arabia comes at a time of year when hundreds of thousands of Saudis traditionally leave the kingdom to escape the summer heat.

Terror expert Hala Mustafa says the latest threats may be an effort to cause financial damage to Western airlines by attempting to scare away passengers during the traditionally busy vacation period.

Whether the statement is from al-Qaida or not, it comes at a time when terror concerns are high in Saudi Arabia. On Sunday in Riyadh, a freelance cameraman was shot dead and a BBC correspondent was wounded in an attack that occurred in an area of the capital known as an al-Qaida stronghold.

Last week al-Qaida militants killed 22 people, including 19 foreigners, during an attack at an oil company compound in the Saudi city of Khobar.