JERUSALEM – Prime Minister Benjamin Netanyahu ordered the immediate closure of the main cargo crossing with the Gaza Strip on Monday in response to Palestinians launching incendiary kites and balloons into Israel.

Netanyahu vowed to use a “heavy hand” against Hamas, the Islamic militant group that rules Gaza, and said more steps would be taken, without elaborating.

Israel’s military said the Kerem Shalom crossing is shut until further notice except for humanitarian aid, medical supplies and food.

Hamas spokesman Fawzi Barhoum called the move “a new crime against humanity” and called on the international community to intervene.

The Palestinians began launching the kites and balloons as part of weekly border protests partly aimed at lifting the Israeli-Egyptian blockade imposed on Gaza more than 10 years ago. Israeli fire has killed over 130 Palestinians at the protests. Israel says it is defending its border and accuses Hamas of using the protesters as cover for attacks.

The incendiary devices have ignited fires that have damaged farmland and forests near the border.