Angry residents from the South blocked 18 of 35 supply trucks on Sunday from entering the Gaza Strip through the Sufa crossing, in the first step of a daily grassroots campaign to force the government to halt such shipments. Supplies to Gaza have been mostly limited to humanitarian assistance and basic staples in the last year, since Hamas's violent takeover forced the closure of the major crossings. But for residents along the Gaza periphery who are fed up with the continued rocket fire, even such basic supplies are too much. On Sunday they caused 18 trucks to turn back while 17 made it through, according to Maj. Peter Lerner, the spokesman for the Coordinator of Government Activities in the Territories. Itamar Gilad, a farmer on the Gaza periphery who helped organize Sunday's protest, said area residents planned to continue their actions on a daily basis. Police said they did not plan to prevent such demonstrations. Gilad called on anyone with "an ounce of Zionism" to join them. It is illogical for the government to hand over food to the very people who are shooting at its citizens, he said. But not everyone agreed. Left-wing activists, in conjunction with Palestinians in Gaza, have planned a joint protest for Monday to call on the government to open all the borders to the pre-June 2007 level and to agree to a cease-fire with Hamas. "They are shelling us because we are starving them," said Adam Keller of Gush Shalom. The activists plan to set out by boat from the Herzliya Marina at 10:15 a.m., the same time that Gaza Palestinians, particularly fisherman, will head out to sea under the slogan, "Let the cease-fire sail." The two groups won't be able to meet, but they will speak to each other by phone while out on the water. The Israeli "siege" of Gaza has held a population of 1.5 million hostage, said Keller. As a result of limited supplies, there is no fuel to purify the sewage, which instead has been dumped into the sea - a move that has polluted the waters and harmed the fish in the area, he said. Keller said all the Gaza borders, including the sea, should be open for imports and exports. The chance for peace was greater if the Palestinians would suffer less, he said. Keller said he was not deterred by the technical problem of who would operate the passages on the Palestinian side in the absence of Fatah, which manned them before the June 2007 coup. He said a solution could be found that would be acceptable to the Israelis and to Hamas. Israel created a situation in which the Palestinian economy is dependent upon it and as a result it has a responsibility to that population, Keller said. "We look forward to the ending of the siege, when it would be possible to sail all the way from the shores of Herzliya and Tel Aviv to those of Gaza and Rafah, and hold meetings between Israelis and Palestinians by sea and land," he said. Yaakov Lappin contributed to this report.