Hamas on Sunday threatened to take military action if the Jerusalem flag march goes ahead on Tuesday as planned, Israel’s Channel 12 reported on Monday.

Citing the Lebanese daily Al-Akhbar, the report said that Hamas conveyed a warning to Israel through Egyptian and United Nations mediators that if the event was not canceled, the Palestinian “resistance” would take actions similar to those it took in May, during “Operation Guardian of the Walls,” when more than 4,000 rockets were fired from Gaza at Israeli population centers.

The original flag march—an annual tradition on Jerusalem Day, which marks the unification of the city after the 1967 Six-Day War—was supposed to take place this year on May 10. It was halted, however, by a rocket barrage from Gaza on Jerusalem, already in the throes of violent Arab rioting. It was this rocket fire that sparked the 11-day “Operation Guardian of the Walls.”