In Tehran, people have gathered in their thousands in front of Tehran University in downtown the city.
They hold Palestine’s flags in their hands, shouting chants against the Zionist regime and its staunch supporter, the US.
A large number of the protesters are young people. Several Iranian cabinet ministers are also among the ralliers in Tehran.
Other cities are also the scene of similar demonstrations.
More than 12,000 Palestinians have died in Israel’s strikes on Gaza, with two-thirds of them being children and women.