Israel cut off fuel supplies to Gaza's 1.4 million residents on Thursday, a day after four Palestinian militants infiltrated the Israeli depot that is the territory's sole source of fuel and shot dead two workers.
The brazen daylight raid in southern Israel threatened to set off a new round of fighting in Gaza after a monthlong lull and could jeopardize recently renewed peace efforts between Israel and moderate Palestinians in the West Bank.
On Thursday afternoon, hundreds of demonstrators began flocking to main intersections of Gaza City, the coastal strip's largest town, to protest Israel's months-old blockade of the territory and the accompanying economic sanctions that have deepened the hardship of ordinary Gazans.
"Rescue Gaza, lift the siege imposed on Gaza," read signs hoisted at one junction.
A mass demonstration against the blockade has been called for Friday.
Three smaller militant factions claimed they carried out the attack on the Nahal Oz fuel depot on Wednesday, but the Israeli government held Gaza's Hamas rulers responsible. It sent tanks, troops and aircraft into the Palestinian territory after the raid, killing at least eight Palestinians, including three civilians.
Wednesday's attack upset more than a month of relative calm following a broad Israeli military offensive that killed more than 120 Gazans, including dozens of civilians. Since the offensive ended in early March, Egypt has been trying to mediate a cease-fire between Israel and Hamas, and the sides appeared to have been honoring an informal truce.
On Thursday, a senior Israeli official warned that more reprisals were in the offing.
"We will chose the time and the place to respond. The blame lies on Hamas as the responsible authority there," Matan Vilnai, Israel's deputy defense minister, told Israel's Army Radio.
Abu Ahmed of Islamic Jihad said the attack deliberately targeted the fuel depot on which Gazans depend.
"This fuel (from Israel) is dipped in humiliation," he said, because people wait for it for hours. "If their fuel means humiliation for us, we don't want it."
Israel did not ship fuel on Thursday and at least two Israeli ministers said Israel should cut it off completely following the attack. Other officials said the flow would be renewed shortly to avert a humanitarian crisis.
Gazans hit hard
Israel sealed its borders with Gaza after the Islamic militant group seized control of the territory in June, and has reduced the flow of fuel, electricity and basic goods. The sanctions have hit the area hard, and on Tuesday, Hamas threatened to blow up Gaza's borders with Israel and Egypt to relieve the strain.
Israel has taken the threat seriously because Hamas breached the Egyptian border in January, allowing tens of thousands of people to pour into Egypt for more than a week before the border was resealed.
Hamas spokesman Sami Abu Zuhri said Thursday that the attack on Nahal Oz was one of the many options Hamas has. "This was the first option, and the beginning of the eruption" against the blockade, he said.
The infiltration also serves as a reminder that Israel, which is conducting peace talks with the rival Palestinian government of President Mahmoud Abbas, won't be able to implement a deal as long as Hamas rules Gaza.
Peace talks resume
Israeli Foreign Ministry spokesman Arye Mekel said the raid would not disrupt peace talks. The two sides hope to reach a final peace deal by the end of the year.
"We decided that we will continue to talk and will not let terrorists have a veto voice on the talks with the pragmatic forces," Mekel said.
Maj. Tal Levram, an Israeli army spokesman, said the militants apparently were planning to carry out a broader attack on a neighboring Israeli village or to kidnap a soldiers, but were thwarted by the arrival of Israeli troops.
Gaza militants frequently attack the Israeli border, but they rarely succeed in getting through. In another daring daytime raid in June 2006, militants tunneled into Israel, killed two soldiers and captured a third. The soldier, Cpl. Gilad Schalit, remains in captivity in Gaza.
Former president Carter steps in
In the United States, the State Department advised former President Jimmy Carter against meeting the leader of Hamas in Syria next week, saying it went against U.S. policy of isolating the militant group.
Carter discussed with the State Department's point person on Israeli-Palestinian issues, David Welch, his plans to meet Hamas leader Khaled Meshaal.
A press release from the Atlanta, Georgia-based Carter Center said the former president was to lead a study mission to Israel, the West Bank, Egypt, Syria, Saudi Arabia, and Jordan, as part of his "ongoing effort to support peace, democracy, and human rights in the region."
The statement said the visit would take place from Sunday until April 21.
"This is a study mission, and our purpose is not to negotiate, but to support and provide momentum for current efforts to secure peace in the Middle East," said Carter, according to the statement. "Our delegation has considerable experience in the region, and we go there with an open mind and heart to listen and learn from all parties."