The police have been notified of the incident and opened an investigation.
The right-wingers are not Gush Katif settlers, but anti-disengagement protesters who took up residence in the Maoz Hayam Hotel, near the settlement of Neveh Dekalim.
The right-wingers encountered passerby close to the Palestinian village of al-Mawassi and started to beat them and even fired a shot.
Stones were thrown at the village.
Four Palestinians who had come to bathe in the sea were injured, the fourth shot in his leg.
Another version of events
However, right-wingers at the hotel presented a different account of events. They told Ynet that the Palestinian group, armed with stones and clubs, first attacked people strolling on the Gaza beach.
"We were shocked to see what had happened and how it was turned against us," they said, adding that "the police, the media, Hamas and the PLO do not want us here, so they are trying to make up different excuses."
Datya Yitzhaki, who heads the anti-disengagement Gaza Absorption Authority, said she spoke with the Israelis youths after the incident and said that they were indeed the ones attacked.
She said the youths were not armed and did not engage in any provocations but were minding their own business when taking a Saturday night walk.
However, police are convinced that one of the hotel guests did fire on the Palestinians and are speaking with witnesses.
Assault provokes shelling
Terrorist groups quickly responded to the incident and fired at least mortar shells at the settlement of Neveh Dekalim.
This is not the first time Palestinians have accused settlers near al-Mawassi of going on the attack.
Gazans said that since the beginning of the al-Aqsa Intifada, these assaults have been a regular occurrence, causing hundreds of thousands of dollars worth of damage.
Soldiers, argue Palestinians, do not respond to requests to investigate settler violence put through the District Coordination Office. The exception was when settlers damaged the tires of IDF vehicles.
In reaction to the assault, Interior Minister Ophir Pines-Paz (Labor) called on the government to close off Gush Katif to "trouble-makers."
Knesset Member Avshalom Vilan (Yahad) asked Defense Shaul Mofaz to remove what he called "the settlorists" (settler-terrorists) from the Maoz Hayam Hotel in Gush Katif.
"This group of crazies fired on Palestinians today, and tomorrow they will fire on IDF soldiers. We must remove this band of bullies as quickly as possible," Vilan said.-- Diana Bahur-Nir, Shmulik Hadad and Ilan Marciano contributed to this article