An audio message attributed to al-Qaeda's deputy leader, Ayman Zawahiri, has called for attacks on American and Israeli interests.
There have been several al-Qaeda messages in the last week
The voice, not confirmed as Zawahiri's, urged retaliation for Israeli raids on the Gaza Strip.
The speaker said Muslims should support Palestinians by focusing on armed struggle, not just demonstrating.
The message was posted on an Islamist website and follows two audio speeches purportedly from Osama Bin Laden.
The graphic accompanying the audio carried the logo of al-Qaeda's media arm, al-Sahab.
"Strike the interests of the Jews, the Americans and all those who participated in the attack on Muslims," the message said.
"Monitor the targets, collect the money, prepare the equipment, plan accurately and then attack."
No specific targets are mentioned, but the voice accuses Egypt, Saudi Arabia and Jordan for forming a "satanic alliance" with Israel and the US to blockade the Hamas-controlled Gaza Strip.
Israel has launched frequent raids on Gaza in an effort to stop frequent rocket attacks launched from the territory.
The messages attributed to Bin Laden last week urged Muslims to fight in Iraq and threatened European countries over the reprint of one of the Muhammad cartoons.