"The people of Jordan are with Hamas," chanted the crowds who called on the Islamist group to resume a campaign of suicide bombings and intensify rocket attacks against Israel.
""Oh Hamas hit them with al-Qassam rockets ... bring the suicide bombers to Tel Aviv ," they chanted, waving the green flags of Jordan's opposition Muslim Brotherhood.
Israel said it had tightened its Gaza blockade last week to counter cross-border rocket fire, but after an international outcry, fuel and aid supplies were partially restored.
Passions prompted by the blockade have run high among Jordanians, many of whom are of Palestinian origin.
Defying tough government curbs on street demonstrations, thousands of mostly pro-Hamas loyalists have in the last few days taken to the streets inside many of the country's squalid camps and poor districts of the capital under the watchful eyes of the authorities to show solidarity with their brethren.
Jordanian officials have been alarmed by Israel's military escalation in recent days and privately worry it would only weaken efforts to advance Arab-Israeli peace talks.
They fear it broadens the popularity of the Islamist movement among a majority of poor Jordanians, many of them living in refugee camps and disenchanted with the U.S.-led Middle East peace process.
"Hamas is winning more supporters every day because it represents the conscience of the nation," Sheikh Hamza Mansour, a leading Islamist deputy said.
Many Jordanians whose families originally come from towns and cities in what is now Israel support Hamas.
The demonstrators lambasted Arab rulers, without naming them, accusing them of standing idly by as ordinary Gazans suffer and called on Egypt to allow freedom of movement for Palestinians.
"Oh rulers ... we want deeds not words ... Gaza is in darkness and you are asleep!," chanted the crowds. "We will not recognize Israel. Israel must be demolished."
Hamas says it will not formally recognize Israel and its 1988 founding charter calls for the destruction of the Jewish state.
Hamas leaders have offered a long-term truce with Israel in return for a viable Palestinian state in the occupied West Bank and the Gaza Strip.
(Reporting by Suleiman al-Khalidi; Editing by Charles Dick)