CAIRO, Egypt (AP) – Egypt’s top Islamic cleric delivered a fierce sermon against terrorism Friday at the main mosque in Sharm el-Sheik, the Red Sea resort struck in deadly bombings a week ago.

Even the Lebanese guerrilla group Hezbollah, branded as terrorist by Washington, says Muslim clerics have to act to curb extremism.

After the unflagging bloodshed in Iraq and this month’s London bombings, the Sharm attack has deepened what has been a growing debate in the Muslim world over how Islam should deal with terrorists who act in its name.

Mohammed Sayyed Tantawi, grand imam of Al-Azhar – one of the Sunni world’s most prestigious institutions – delivered the sermon at Friday prayers in Sharm el-Sheik’s “Peace Mosque,” packed with hundreds of worshippers still reeling from the July 23 bombings, which killed scores of Egyptians and foreign tourists.

Tantawi told worshippers that “even polytheists who come to Egypt to see its civilization, who didn’t come to harm you, you have to protect them and treat them in a good way.”

The cleric used the Arabic word “mushrikin” – “polytheists” – a term heavy with negative connotations in Islam. The Quran, Islam’s holy book, repeatedly denounces “mushrikin,” while accepting Jews and Christians as fellow monotheists. Islamic radicals often rail against polytheism and its followers.

Those who killed dozens of innocents, “have no justification,” and if they claim they are obeying orders of Islam, “then they are liars, liars and charlatans, and Islam disavows them,” he said.

“The aggressors who blow up themselves, their cars and bombs against innocent men, women and children will not be given any mercy by God … they will be cursed by God and his angels,” Tantawi said.

Tantawi has emerged as a strong voice against terrorism in recent months. In early July, he harshly condemned Islamic insurgents in Iraq – who even some moderate Muslims feel are fighting for a just cause against U.S. occupation – saying all Iraqis and Arabs should unite to purge Iraq of “their filth and viciousness.”

Egyptian investigators have been focusing on the likelihood that homegrown Islamic militant cells in Sinai – possibly with international links – carried out the Sharm bombings, in which two car bombs and a knapsack bomb ripped through a luxury hotel, a neighborhood full of Egyptians and the entrance to a beach promenade. The official death toll stands at 64, but hospitals say bodies still uncounted could bring it to 88.

With every terror attack, Arabs and Muslims have been struggling to strike a balance between condemning bloodshed and pointing to U.S. policies in Iraq and Israel they say fuel Islamic militant violence. Debate has focused on whether reform is needed to purge extremist teachings.

In Lebanon, the militant Shiite Muslim Hezbollah said immediately after the Sharm attack that “mass murder attacks against innocent people … require a decisive stance by (Muslim) clerics” against violence.

Hezbollah is considered a terrorist organization by the United States, which accuses it of supporting Palestinian militants against Israel. But in Lebanon, it’s seen as a nationalist force after its long fight against Israeli troops that occupied southern Lebanon until 2000.

The group’s stance on violence is becoming more nuanced. It sharply opposes the U.S. troop presence in Iraq – but with its Iraqi Shiite brethren frequently falling victim in bombings, it has grown more vocal in condemning the insurgency in Iraq.

Lebanon’s most senior Shiite cleric, Grand Ayatollah Mohammed Hussein Fadlallah – who had past connections with Hezbollah, but broke with the group – said after the Sharm attacks that all Muslims must condemn such attacks, which he blamed on “backward minds that do not understand Islamic texts.”

But in his sermon Friday, he said the “evil phenomenon” of terrorism “stems from the policy of arrogance (by the United States and Israel).”

At a small mosque in Cairo’s Heliopolis suburb, the Friday preacher appealed to his congregation, trying to explain the proper meaning of “jihad” – a word often translated as “holy war” but more broadly meant as a “struggle” for Islam against oppression.

Jihad, he said, is by word, not by action.

“Oppression should be fought, but every thing has rules,” he said in a sermon blared by loudspeaker across the neighborhood. “The world has become a small village, and with good words, we can influence and impress the rest of the world, not by horrific actions.”