Among the 27 activists and crew members of the vessel that sailed from Cyprus were Mairead Maguire, a Nobel Peace Prize winner who led a campaign against violence in Northern Ireland; Mustafa Barghouti, an independent Palestinian legislator from the West Bank; two Israeli citizens; and individuals from various countries including Britain, Italy and the United States.
The voyage, as was the last one, was organized under the auspices of the Free Gaza Movement, a Palestinian advocacy group based in El Cerrito, Calif.
In late August, the first two boats arrived together in Gaza despite Israeli threats to stop them. Israeli Foreign Ministry officials said at the time that there had been a last-minute decision to let the boats through to avoid a public relations debacle, and not to play into the hands of people they described as provocateurs.
This time, too, Israeli officials had stated that the boat would not be allowed to reach Gaza, yet it was allowed to proceed without hindrance.
“It was decided at the highest levels to allow them to enter,” said Yigal Palmor, an Israeli Foreign Ministry spokesman, without explanation.
Hamas, the Islamist group that took control of Gaza in June 2007, is classified as a terrorist organization by Israel, the United States and the European Union. Israel strictly limits the volume and type of goods entering the area by land, though the economic embargo has eased somewhat since a truce took effect in June.
Still, Israel maintains a policy of isolating the area. The authorities denied entry this week to 120 international academics and health professionals who had applied to attend a conference organized by the Gaza Community Mental Health Program, which offers a range of local services and is supported by the World Health Organization and other international bodies. The conference focused on the state of mental health in Gaza in light of the blockade.
The international experts participated by video conference from Ramallah, in the West Bank.
Before dawn on Wednesday, Israeli forces shot dead a Palestinian man in the village of Yamoun, near Jenin, in the northern West Bank. A spokesman for the Israeli military said that the man, Muhammad Abahreh, 67, had fired a hunting rifle at a force that was on a routine operation in the area, and that the soldiers had fired back.
Mr. Abahreh’s son, Taher, told news agencies that his father, a farmer, was guarding his livestock against rustlers in an enclosure just outside the village when he was shot in the dark.