Israel decided to shut down the crossing and limit the Palestinian coastal enclave's fishing zone in a crackdown to target the terror organization responsible for border protests now in their fourth month.
"Israel's Prime Minister Benjamin Netanyahu authorizing further steps to increase the siege (on Gaza) and prevent goods and materials from coming into Gaza is a new crime against humanity, which is added to the Israeli occupation's black list of actions against the Palestinian nation and the strip's residents," Hamas said in a statement
"The silence of the world and the region about the crime of the 12-year-old blockade over Gaza encourages the Israeli enemy to proceed with its actions, which contradict humanitarian and international law," the terror organization added. "Hamas calls upon the international community to quickly act to prevent (Israel's) crime and its grave ramifications. (The international community) has to act to end the siege over Gaza and Israel's crimes against the strip and its residents," the terror organization went on.
"Israel's government is solely responsible for this extremist and racist policy," Hamas concluded.
The Palestinian Islamic Jihad's reaction was harsher saying, "Increasing the siege over Gaza constitutes a declaration of war. The resistance will never sit idly by."
The strip's private sector was caught completely off guard by Israel's decision to immediately close the Kerem Shalom crossing as a response to the kite and balloon terrorism. Palestinian businessmen expressed concerns about their and Gaza's economic future.
A Gazan source told Ynet, "100 days ago Hamas launched its 'March of Return' campaign to ease the situation in the strip. And what eventually happened? The blockade became worse."
"Since Hamas launched the campaign, Gaza's situation has deteriorated. (Israel's) decision is a hard blow for Hamas, one it didn't expect," the source added.
"Preventing import and export of goods through the Kerem Shalom crossing means a quick collapse of (Gaza's) economic industries, businessmen and companies going bankrupt and a drop in local fiscal income," one of Gaza's businessmen who preferred to stay anonymous told Ynet.
The businessman also warned that education and health services could be affected. "It will cause a destructive chain of events both on the economic level as well as on the humanitarian level in the strip."
The Palestinian Committee for the Coordination of Goods in the Gaza Strip updated all the merchants on the Israeli decision. The committee's head, Raed Fatuh, said the decision affects all goods exported from Gaza abroad and to the West Bank and most of the goods imported to the strip.
A pro-Hamas senior Palestinian journalist in Gaza accused Prime Minister Netanyahu and Defense Minister Avigdor Lieberman of only seeking to apply additional pressure on Hamas.
According to the journalist, Israel and Mahmoud Abbas are joining forces to implement their punitive measures against Gaza and causing escalation.
An IDF statement, and separate remarks by Defense Minister Lieberman, linked the new measures to fires from incendiary kites and helium balloons that have been flown over the border since the protests began on March 30, consuming swathes of Israeli farmland.
Nevertheless, the IDF stressed Kerem Shalom would remain open for the transfer of specially approved humanitarian goods by the coordinator of government activities in the territories.
It also said Gaza's fishing zone would revert to 11 km (6 miles) after it was temporarily expanded to 17 km (9 miles).
In response to the fishing zone being reverted, the "March of Return" organizers announced another flotilla from Gaza heading to Cyprus would depart on Thursday. Palestinians who are wounded and in need of medical treatment will be on board.
This flotilla follows the one that departed Gaza on Nakba Day in protest of the US Embassy move to Jerusalem on May 14. It went mostly unnoticed because of the deadly clashes on the Gaza border fence that day, when more than 60 Palestinians were killed.
The navy stopped the boat at sea, dragged it to the Ashdod port, detained the Palestinians on board and returned most of them to Gaza through the Kerem Shalom Crossing.