Al Qaeda's No. 2 warned Palestinians in Gaza against accepting a truce with Israel in an audio message posted on extremist Web sites, an Internet monitoring service said Monday.

Egyptian-born Ayman al-Zawahiri said "Israel's Arab aides" are trying to impose a truce in Gaza to defeat the Palestinians and he called on them to be steadfast while Jewish targets are attacked around the world.

"The jihad to liberate Palestine and all the homelands of Islam mustn't cease, and if the field tightens in one place, it widens in other places, and Crusader and Jewish targets are spread all over the world," he said in a transcript of the speech provided by the U.S.-based SITE Intelligence Group, which monitors Islamic extremist Web sites.

Zawahiri described ongoing negotiations for a cease-fire in the Gaza Strip as "plots and conspiracies" to defeat the Palestinians after Israel's "aircraft and artillery" failed.

Egypt has been mediating between Israel and Gaza's militant Hamas rulers in an effort reach a long-term truce after three weeks of fighting in December and January. Israel attacked the Gaza Strip on Dec. 27 to put a halt to Hamas rocket fire in a campaign that killed nearly 1,300 Palestinians and 13 Israelis.

Zawahiri said Islamic militants would help the Palestinians by mounting attacks everywhere, "for the entire world is our field against the targets of the Zionist Crusade."

The recording, which focused primarily on Islamic militant successes in Somalia, was the third Zawahiri has posted this year dealing with the recent Israeli offensive in Gaza. The terror network's chief, Usama bin Laden, also issued an audio message on Gaza in January, urging Muslims to launch a jihad against Israel.

Al Qaeda holds little influence among Palestinians but the network's Gaza-related postings are likely meant to harness Muslim anger about the Israeli offensive and direct it against Arab regimes friendly with the Jewish state.

The authenticity of the 25-minute recording could not be independently confirmed, but it was posted on an Islamist militant Web site known as a clearing house for Al Qaeda messages.