Tens of thousands of Iranians have taken part in state-sponsored anti-Israeli rallies across the country to mark the annual Quds Day.
Some protesters set Israeli and U.S. flags on fire while others chanted "Death To America" and "Death To Israel", Iranian media reported.
The day was established by the founder of the Islamic republic, Ayatollah Ruhollah Khomeini, to show support for Palestinians and opposition to Israel, which Iran does not recognize.
Attending the rally in Tehran, Iranian President Hassan Rohani said regional conflicts make it increasingly difficult to support the Palestinian cause.
"Today, due to the divisions in the Islamic world, the presence of [Sunni extremists] and terrorists in the region, we are far away from the ideal of liberating Palestine," Rohani was quoted as saying by Iranian news agencies.
Meanwhile, the deputy head of the Islamic Revolutionary Guards Corps, Hossein Salami, warned that Lebanon's Hizballah "has 100,000 missiles that are ready to hit Israel."