The demonstration was backed by the ruling party, opposition groups and other organisations.
A few members of Jordan's parliament burned the Israeli flag under the parliament dome while in session on Sunday, after calling for the expulsion of the Israeli ambassador to Amman.
In Lebanon, hundreds of Lebanese and Palestinian refugees staged a sit-in near the United Nations office in central Beirut.
The protesters held banners calling on the global body to put pressure on Israel to end the attacks that have killed more than 280 people.
The protest was organised by the Lebanese-branch of the Muslim Gamaa group, along with Hamas and other groups. Lebanon is host to more than 400,000 Palestinian refugees living in 12 camps across the country.
Al Jazeera's Rula Amin, reporting from Beirut, said that people were demanding more decisive action from their leaders.
"From the people we have heard very critical remarks, not only against Israel, but also against Arab governments. Many were angry at the Egyptian government, they feel they needed to do more," she said.
The Hezbollah movement, which fought a 33-day war with Israel in 2006, has condemned the attacks as a "war crime and a genocide that requires immediate action from the international community and its institutions".
"I'd like to say ... that Gaza will remain steadfast in the face of Americans and Zionists whatever the plots and conspiracies hatched by tyrants and arrogant enemies"
Palestinian ambassador to Iraq
In a statement, the group called on Arab countries to "take a firm stand and exert its utmost efforts against the Israeli barbarism - which is covered by the US - and the international community to stop this ongoing massacre".
The Arab League will not meet to discuss a common response to the Israeli assault until a summit in Doha, Qatar, on January 2.
Arab foreign ministers were due to hold an emergency meeting on Sunday, but the meeting was postponed until Wednesday.
Amr Moussa, the Arab League secretary-general, said the delay was because many ministers were busy in separate meetings of two Arab regional groups - the Gulf Co-operation Council (GCC) and the Maghreb Union.
"The time worries us very much because of the delay in holding the ministerial meeting but we will not remain silent and consultations are continuing," he said.
The attack will, however, be discussed by the GCC, which on Saturday described the situation as "barbaric" and "ugly".
Meanwhile in Damascus, the capital of Syria, an estimated 5,000 people congregated in the Yusif al-Azmeh square, shouting slogans and cluttering the horizon with the flags of Hamas, Islamic Jihad, the PLFP, Hezbollah, Syria, Iraq, and Palestine.
|Palestinian youths clashed with Israeli troops in a Jerusalem refugee camp [AFP]
Many were bussed in for the demonstration, suggesting that it was government orchestrated, though some protesters insisted that their attendance was not obligatory.
One lorry slowly circled the square, covered in Hamas banners and carrying masked men dressed in white with fake suicide belts. From loudspeakers, Hamas supporters called for "jihad" against Israel and led their followers in fist-pumping chants calling for "struggle in the name of God".
In other parts of the square some burned Israeli flags. Others praised Bashar al-Asad, the Syrian president, while calling on Egypt's Hosni Mubarak to take a stand against Israel.
"I came here to stand alongside my brothers in Gaza and to stand against the Israeli aggression and rape of Gaza. Israel doesn't want peace," said Ismael Balaan, a 45-year-old telecommunications worker.
Nearby, followers of Muqtada al-Sadr, an Iraqi populist leader opposed to the US presence in his country, dressed in the black uniform of al-Sadr’s militia, danced while chanting against the US and Israel.
"We are protesting for the oppressed people in Gaza and against the Israeli bombing that has killed women and children," said Akram al-Musawi, a black-turbaned Sadrist. "We will resist all oppressors and anyone that kills women and children whether it's in Iraq, Lebanon, or Palestine."
One Iraqi born Palestinian, who asked not to be named, was critical of the demonstration, which he believed to be government orchestrated.
"If the Syrian government really cares about Palestine why don't they let in the Palestinians stuck in the al-Tanf refugee camp on the border?" he said, referring to the Iraqi-Palestinians living in the no-mans-land between Iraq and Syria
Demonstrations also took place across Iraq.
Dozens of Palestinian refugees gathered in Baghdad's eastern Baladiyad neighbourhood chanting anti-Israeli slogans and waving messages of support for Gaza.
Dalil al-Qasoos, the Palestinian ambassador to Iraq, said: "I'd like to say to my relatives and to my people in Gaza that Gaza will remain steadfast in the face of Americans and Zionists whatever the plots and conspiracies hatched by tyrants and arrogant enemies."
In Mosul, a suicide bomber blew himself up among a crowd of demonstrators killing at least four people and injuring 20 others, police said.