The Islamic Jihad militant group in the Gaza Strip announced a unilateral cease-fire Monday evening to end two days of heavy fighting with Israel.

In a short statement, the Iranian-backed group said it had completed its “retaliation” for Israel’s killing of three members. But it said it would respond to any further Israeli “aggression.”

Earlier Monday, the Islamic jihad militants had resumed their intense bombardment of southern Israel, with some rockets slipping through Israel’s Iron Dome defense system and one landing in the yard of a kindergarten.

There was no word of casualties, but the violence threatened to unleash a new round of hostilities just a week before Israel heads to elections. Israeli Prime Minister Benjamin Netanyahu threatened Gaza’s Hamas rulers with a “war” if the new round of rocket fire continued, ramping up his rhetoric amid the final stretch of his campaign.

Netanyahu’s interview was interrupted with news of fresh air raid sirens warning of incoming rockets, as Palestinian militant fire resumed midday after a morning lull. The Israeli military said it identified 14 rockets fired in the hour-long spree, of which it intercepted 12. Shortly after, the military began striking sites linked to militants in Gaza.

The Islamic Jihad militant group fired at least 20 rockets on Sunday after Israeli forces killed a Palestinian militant who tried to place a bomb along the Israel-Gaza barrier fence, and then removed his body with a bulldozer. The image outraged Palestinians, leading to the rocket fire. Israel responded by striking targets linked to militants in Gaza and Syria. As a precaution, schools were closed in Israeli areas adjacent to Gaza and restrictions placed on outdoor public gatherings.

Israel and Hamas have engaged in three wars between 2008 and 2014 and several intense rounds of violence after that. Israel and the Islamic Jihad group engaged in a heavy round of fighting last November after the Israeli military killed a top Islamic Jihad commander. Since then, Israel and Gaza’s more powerful Hamas group have been working through Egyptian mediators to cement an informal cease-fire. But Islamic Jihad has continued to try to carry out attacks.

The sudden exchanges after months of relative calm put Israel’s tense security situation back on the agenda a week before the the country’s third election in less than a year. The campaign has thus far largely focused on domestic issues and Netanyahu’s precarious legal situation after he was indicted on corruption charges.