Together, the two messages appeared to be a more direct push by the terror network's leadership to use widespread anger over the Gaza violence to whip up support.
Zawahiri is listed on the Federal Bureau of Investigation website as one of its most wanted terrorists, and the Associated Press reports that the two messages have raised concerns Al Qaeda could be planning new attacks in the West.
The increased focus on the Palestinian issue also reflects the terror network's desire to show it is up to date on the latest events in the region, even as al Zawahri, bin Laden, and other leaders are believed to remain in hiding in the Afghan-Pakistan border region.
"The nearest jihad battlefield to support our people in Palestine is the battlefield of Iraq … It should be taken care of and supported," he said in the audiotape released on Thursday.
"Palestine cannot be retaken by negotiations and dialogue, but with fire and iron."
Earlier, bin Laden warned Europe of a "reckoning" for publishing controversial cartoons satirizing the prophet Muhammad. Bin Laden said publishing the "insulting drawings" was a greater crime than Western forces targeting Muslim villages and killing women and children. He said the publication of the cartoons was part of a "new crusade," involving the Catholic Pope Benedict XVI. The Vatican rejected the accusation, The New York Times reports.
The audio message was addressed to the "intelligent ones in the European Union" and had been posted on a militant website, and an English translation was distributed by the SITE Intelligence Group in Bethesda, Md. In the five-minute message, the speaker said there would be a "severe" reaction to the publication of cartoons that many Muslims consider offensive to the prophet Muhammad. Bin Laden's message coincided with the fifth anniversary of the beginning of the Iraq war, reports the Associated Press.
Zawahiri's message also referred to the republication of cartoons depicting the prophet Muhammad, in what some see as rising concerns in Europe over the portrayal of Islam in some sections of the media.
The website of Geert Wilders, a far-right wing Dutch lawmaker, who had been expected to release a controversial film on Sunday, was suspended, the International Herald Tribune reports. The website had shown the unreleased film's title, "Fitna," and an image of Islam's holy book, the Koran, which the film is said to criticize. The website now shows a note indicating that the US company, Network Solutions, is investigating whether the website's contents violate its terms of service.
The recent messages from Al Qaeda leaders also coincide with the conclusion of an Israeli offensive in Gaza earlier in March. Israel said it was seeking to curb Palestinian militants firing rockets against nearby Israeli towns. Some 120 were killed, including civilians. The fighting has complicated and stalled a new round of Israeli-Palestinian peace talks.
In a visit on Saturday, Vice President Dick Cheney said US support for security in Israel was "unshakeable," Bloomberg reports. Mr. Cheney also warned Palestinians against resorting to terrorism and rocket attacks to add pressure for an independent state.
Cheney visited the city of Jerusalem and the West Bank as part of a drive to push the two sides toward a vision for a Palestinian state. The push emerged as a top priority for President Bush in his final year of office.
On Sunday, Mr. Abbas told Cheney the US needed to give more support to peace talks. Those talk are being mediated by Egypt and are aimed at securing a truce between Israel and Hamas, The Washington Post reported.
The comments were a recognition that violence in Hamas-dominated Gaza was blocking progress toward the broader goal of the new talks.