Defense Minister Ehud Barak ordered Israel's Gaza crossings closed Tuesday morning following rocket and mortar attacks by Gaza terrorists aimed at southern Israel.

A shipment of humanitarian supplies planned for delivery on Tuesday afternoon was cancelled due to the attacks.

The closure of the crossings to commercial traffic has been a frequent occurrence since intensified rocket and mortar attacks from Gaza resumed last month.

Four Kassam rockets and a number of mortars were fired at various Jewish communities in the western Negev earlier in the morning. Several of the missiles exploded in open areas in the Eshkol Regional Council district and a mortar shell struck the Sdot Negev Regional Council district. No one was injured and there were no reports of damage in any of the attacks.

The Islamic Jihad's al-Quds Brigades terrorist group took responsibility for the rocket fire. The terrorists said the attacks were carried out to avenge the death of a 23-year-old commander in northern Israel Tuesday morning while trying to escape arrest by IDF soldiers at an internet café in a village near Jenin.

Any political comment on the situation with Gaza is unnecessary, declared Barak, because the so-called "calm will be met with a calm, but if the situation calls for it, we will react in the manner and time which we see fit."

The defense minister, who was visiting an IDF armored corps base in the Golan Heights when he made the comment, added that he was recommending that "everyone leave the matter to the professional echelons."