Wearing white T-shirts dyed in red to signify Friday's killings, protesters lay on the ground at an Israeli checkpoint at Kalandia, 10km north of Jerusalem, on Sunday.
Abdullah Abu Rahma, head of the Committee against the Separation Wall in Ramallah said: "We are Israelis, Palestinians and internationals united against the oppression of the occupation.
"We call on all peace-loving people around the world to pressure Israel to stop this slow-motion genocide against our people. They are killing us - one baby at a time, one family at a time."
Peretz resignation calls
Israeli soldiers scuffled with the protesters, preventing them from going through the checkpoint after declaring it "a closed military zone."
The protesters demanded that Amir Peretz, the Israeli defence minister, resign from his post, which he assumed weeks ago.
A Palestinian girl weeps next to
her father's body on a Gaza beach
One Israeli protester told Aljazeera.net that "we thought Peretz would be a peace asset in the new government, we didn't know that children and babies would be murdered under his command".
In addition to scores of Israeli peace activists, more than two dozen foreigners, many of them affiliated with the International Solidarity Movement (ISM) participated in the protest.
One placard carried by the protesters urged: "Stop killing the children, prosecute the child-killers."
The protest is the second in the past 24 hours.
More than 300 Israeli peace activists, most of them affiliated with the Gush Shalom (Peace Bloc), staged a sit-in outside the Tel Aviv home of Dan Halutz, the Israel Defense Forces' chief of staff, on Saturday night.
The protesters, who included two leftist Knesset members, called on the Israeli public to speak up against the "crimes of the occupation in Gaza."
"We thought Peretz would be a peace asset in the new government, we didn't know that children and babies would be murdered under his command"
Dov Hanin, a leftist legislator, condemned the killings, saying "the Israeli army was killing children in our name."
Among participants in the protest in Tel Aviv was Dana Olmert, daughter of the Israeli prime minister, Ehud Olmert.
Israeli groups' call
On Sunday, five Israeli peace groups, including the main Israeli human rights organisation, B'tselem, urged the Israeli government to stop killing Palestinian civilians.
The five organisations, in a letter to Peretz that was made available to Aljazeera.net, described the killing of the Ghalia family members as a "horrible addition to an already horrible toll" of Palestinian civilians by the Israeli army.
The letter pointed out that since outbreak of the second Palestinian Intifada in September 2000, the Israeli army and paramilitary Jewish settlers have killed 3446 Palestinians, including 704 children and minors.
The letter said that at least 1647 of Palestinian victims were civilians and played no part in hostile activities.
The figures, the letter pointed out, did not include 246 people who have been assassinated in what Israel calls "targeted killings".
The letter said that while Israel had a right to defend its citizens against attacks by Palestinian resistance groups, it was unacceptable that a sovereign state commit illegal actions that amount to war crimes.
Israel has said the killings on the Gaza beach were a mistake, although it has not admitted responsibility.
A senior Israeli commander on Sunday said the investigation into the killings has raised many "question marks" about whether Israeli forces were involved.
Major General Yoav Galant, head of Israel's southern command, said the army is exploring the possibility that an artillery shell hit the civilians but that the cause of the explosion remains unclear.