JUNE 17, 2021 11:08 PM

Men prepare incendiary balloons near Gaza city to launch across the border fence towards Israel, June 16, 2021. (Fatima Shbair/Getty Images

(JTA) — The Israeli military hit Hamas sites in Gaza with rockets for the second time this week on Thursday night in retaliation for incendiary balloons sent in to spark fires in southern Israel, raising fears that the recent Israel-Hamas cease-fire could be in jeopardy.

The Israel defense forces said it struck Hamas military compounds and rocket launch sites, according to CNN. Hamas did not send rockets in response.

The IDF had sent a round of rockets into Gaza on Tuesday after it lost patience with the deluge of balloons filled with flammable material sent into Israel by Palestinians near the Gaza-Israel border. Hamas praised the attacks — which started a series of fires but did not injure any in the Israeli countryside — although the militant group did not take responsibility for organizing them.

The cease-fire last month brought an end to over a week of intense fighting between Israel and Hamas that killed about 230 Gazans and 12 Israelis.