Tens of thousands of Lebanese Shi'ite protesters, chanting "Death to America, Death to Israel", massed in Beirut yesterday, demanding an end to Israeli strikes on Gaza that have killed at least 325 Palestinians.
In the Jordanian capital, Amman, about 20,000 people staged a demonstration organised by the mainstream Muslim Brotherhood, while in Cairo 1,000 people rallied to show solidarity with Gaza Palestinians.
Elsewhere, about 1,000 demonstrators gathered outside the Israeli embassy in London for a second day yesterday. The crowd, chanting "Free Palestine", had to be controlled by riot police.
"In Gaza today we face, as a nation, a battle against the fate of Palestine and not the fate of the Hamas government," Hizbollah leader Sayyed Hassan Nasrallah told a throng of demonstrators in Beirut's southern suburbs via videolink.
"I join my voice to the voices of other Palestinian leaderships that have called for a third intifada (uprising) in Palestine and other intifadas in both the Arab and Islamic worlds..." he said.
"I believe that defending Gaza and the people of Gaza means that the nation should offer the blood of martyrs," Mr Nasrallah said.
His comments echoed those of Hamas leader Khaled Meshaal on Saturday. The Israeli raids on Hamas-controlled Gaza are some of the most destructive in 60 years of Israeli-Palestinian conflict.
In the Amman rally, protesters urged Hamas to resume a campaign of suicide bombings and intensify rocket attacks.
"Oh Hamas, we are your soldiers... hit them with al-Qassam rockets... bring the suicide bombers to Tel Aviv," they chanted, waving the green flags of the Muslim Brotherhood, the ideological ally of Hamas and the leftist opposition.
Many Jordanians, whose families originally came from towns and cities in what is now Israel, support Hamas.
The demonstrators lambasted Egyptian President Hosni Mubarak and urged his country, which has been cooperating with Israel for months in the blockade of Gaza, to allow freedom of movement for Palestinians.
In the Cairo protest outside the Journalists Union building, the crowd, which included Islamists, leftists and Arab nationalists, shouted slogans in support of Gaza Palestinians and condemning Arab governments, including that of Egypt.
They called on the Egyptian government to open the Rafah crossing and stop collaborating with Israel in the blockade of the impoverished coastal strip and its 1.5 million inhabitants.
About 1,000 riot police, armed with batons and shields, penned the protesters into a narrow area on the steps of the union and along the nearby pavement.
Witnesses in Saudia Arabia's oil-producing Eastern Province said police fired rubber bullets to break up a pro-Palestinian protest yesterday, injuring up to eight people, but a government official denied the report.
Many governments in the Arab world are seen as collaborators with the US or Israel by popular Islamist movements.
Similar protests took place in many Arab countries on Sunday.