A crippling Israeli blockade on the Hamas-ruled Gaza Strip is creating food shortages.  Robert Berger reports from the VOA bureau in Jerusalem.

A U.N. flour warehouse in Gaza is empty a week after Israel halted shipments in response to Palestinian rocket attacks.  A warehouse containing canned meat is also about to run out of supplies, affecting hundreds of thousands of Palestinians.

U.N. spokesman Chris Gunness condemned the rocket attacks.

"They are an abomination and they have to stop," Gunness said.

But he said cutting off food supplies is collective punishment.

"We would love to see the borders open because you know, we have supplies going to blind children in Gaza; they are not firing rockets and they should not be punished," Gunness said.

A wave of clashes during the past week is testing a five-month-old ceasefire between Israel and the Islamic militant group Hamas that rules Gaza.  

Fighting erupted when Israel launched a cross-border raid to destroy a tunnel the army said was going to be used to kidnap Israeli soldiers.  Seven Palestinian gunmen were killed in the raid.  Hamas has retaliated with rocket and mortar fire.

Israeli military spokesman Peter Lerner says the flow of supplies into Gaza depends on Hamas halting the attacks.

"At the end of the day, the Gazan authority, namely the Hamas terrorist organization, they have to control what is going in and around Gaza," Lerner said.   "Otherwise the crossings will remain closed."

Israel has also barred journalists from entering Gaza, prompting this protest from Foreign Press Association Chairman Steven Gutnik.

"This is a serious violation of freedom of the press," Gutnik said.  "It is essential that journalists be allowed to enter the Gaza Strip since it is the foreign media that serves as the world's window into Gaza."

Israel says it will not be business as usual in Gaza as long as rockets are being fired across the border.