JERUSALEM — After a monthlong lull in the terror attacks that shook Israel, two Islamic militant groups have threatened to resume their suicide bombing missions.

The Izzadin Kassam Brigade, the armed wing of Hamas, said in a leaflet distributed Tuesday to news agencies here that it was "not going to give up and is going to punish everyone who declared war against Hamas."

The threat, which came on the eve of Passover, was issued a day after a smaller fundamentalist group, Islamic Jihad, promised new suicide attacks against Israel.

The groups claimed responsibility for four suicide attacks against Israel in late February and early March that claimed the lives of 58 victims.

In their leaflet, the Hamas group referred to their suicide attacks as "the wonderful martyrdom operations."

Meanwhile, Israel Defense Force Chief of Staff Lt.-Gen. Amnon Lipkin-Shahak told the Knesset's Foreign Affairs and Defense Committee Tuesday that Hamas and Islamic Jihad are "highly motivated to continue attacks" against Israel.

"All you need is a detonator, explosives and the scum willing to kill themselves," he said, adding that such violence is difficult to fight.