Thousands of people Friday demonstrated against Israel's attacks on the Gaza Strip in widespread protests stretching across the Middle East, Asia, Africa and even some scattered protests in Europe.

Similar protests have been held daily across the Middle East since Israel launched the bombing campaign last Saturday. But these gatherings held mostly after Friday prayers were larger — mainly because Friday prayers are a traditional gathering opportunity for Muslims — and seemed to be more far-reaching in the number of countries where protests occurred.

The Israeli offensive has killed more than 400 Palestinians and sparked outrage among the Arab public. Israel says its offensive is aimed at silencing Hamas rockets.

In Tehran, a crowd of about 6,000 stretching for a half-mile marched from prayers at Tehran University to Palestine Square, chanting "Death to Israel" and "Death to America" and burning Israeli flags.

• Click here for photos.

Iranian Foreign Minister Manouchehr Mottaki warned Israel that entering Gaza "by land will be the biggest mistake of the Zionist regime." He vowed Israel would be "defeated" in a ground attack.

Iran is a major backer of Hamas, which controls the Gaza Strip, giving it millions of dollars — and weapons and rockets, according to the U.S. and Israel, though Tehran denies arming Hamas.

In Egypt, authorities clamped down hard to prevent protests Friday. Hundreds of riot police surrounded Cairo's main Al-Azhar Mosque, where a rally had been called, and scuffled with would-be protesters, keeping most from approaching.

Police also arrested 40 members of the Muslim Brotherhood, an opposition group that had called for pro-Gaza rallies.

More than 3,000 people marched in solidarity with Gaza in the northern Sinai city of el-Arish, Egypt's closest city to Gaza.

Many governments in the Arab world such as Egypt have been wary about protests at home over Israel's Gaza assault lest the protests spiral out of control.

In Jordan, police fired volleys of tear gas and scuffled with dozens of protesters who tried to push through barriers to reach the Israeli Embassy in Amman. A few of the protesters threw stones at police, but the security forces dispersed the group, arresting several.

About 30,000 Jordanians gathered at a stadium in Amman shouting their support for Gaza and calling for the abolition of the Jordanian-Israeli peace treaty signed in 1994.

More than 10,000 Muslims marched through Indonesia's capital Jakarta to protest the ongoing bombing raids in Gaza, aiming fake missiles labeled "Target: Tel Aviv, Israel" at the U.S. Embassy.

Protests were also held after Friday prayers in other cities in the world's most populous Muslim country, in what was the largest turnout since Israel began the operation.

In the Afghan capital of Kabul, about 3,000 people gathered outside a prominent mosque, according to police estimates. Men in the crowd threw stones and shoes at an effigy of President George W. Bush.

Dozens of demonstrators gathered in the Philippines capital Manila, carrying placards saying Israel is a "butcher of children" and accusing it of war crimes.

In Turkey, Israel's closest ally in the region, some 5,000 people denounced the Israeli raids outside a mosque in Istanbul, burning Israeli and U.S. flags and reciting funeral prayers for the victims. The state-run Anatolia news agency says similar protests were held in several other Turkish cities.

In Syria, some 2,000 marched in a Palestinian refugee camp in Damascus, carrying Palestinian flags and chanting "jihad will unite us," and later burned an Israeli flag.

In Sudan, thousands marched in downtown Khartoum from mosques to the main Martyrs Square, urging Muslims to jihad and denouncing Israel and America.

Small protests erupted as well in the Palestinian territories.

In the West Bank city of Ramallah, thousands demonstrated in solidarity with Gazans, calling for Palestinian unity and accusing Arab leaders of silence over Israel's bombardment.

Ex-Eurythmics singer Annie Lennox and other celebrities, including activist Bianca Jagger, comedian Alexei Sayle and politicians including former London mayor Ken Livingstone, held a press conference in London demanding Israel halt the onslaught.

In Bern, Switzerland, hundreds of people marched, calling for an immediate cease-fire in Gaza and demanding that the international community impose sanctions against Israel.

Russian authorities detained about 37 people after a small protest outside the Israeli Embassy in Moscow demanding an end to attacks on the Gaza Strip. The protests included members of Russia's many Muslim minorities.

Hundreds of Muslims held a rally at the main mosque in the Kenyan capital of Nairobi after prayers, hoisting banners that said "Palestinian Blood Is Human Blood" and shouting for Kenya to sever ties with Israel.