In the first incident that happened overnight, an Israeli tank opened fire at three Palestinians, killing them immediately, Wail al-Dahduh, Aljazeera's correspondent in Gaza said on Thursday, quoting Israeli sources.
"Their torn up bodies were sent to Abu Yusuf al-Najjar hospital," he added.
In the second incident, Israeli soldiers opened fire at another group of people, who the army said approached the border with Egypt, killing one and injuring two others, the correspondent reported.
The two injured were captured and transferred to the Israeli Suruka hospital in Bair al-Saba, east of the Gaza Strip.
However, sources said one of the two injured had died while the other was still receiving medical treatment in the intensive care unit.
No Palestinian sources have reported the incidents and resistance factions have not issued any statement, said the correspondent.
"It is still unclear if the five Palestinians killed belonged to any of the factions," he added.
Assault on candidate
Meanwhile, Palestinian presidential candidate Mustafa al-Barghuthi (not the imprisoned intifada leader Marwan al-Barghuthi) and some of his guards came under an Israeli attack close to the Shavi Shamron settlement, near the West Bank city of Nablus, sources told Aljazeera.
Israeli soldiers held al-Barghuthi and his guards for some time after beating them up. Al-Barghuthi was later taken to Nablus hospital.
Al-Barghuthi (L) was taken to
hospital following the attack
"We were coming back form Jenin, heading towards Ram Allah when the Israeli army stopped our car at Sanur crossing and forced us out," al-Barghuthi told Aljazeera.
"I explained to them that I am a presidential candidate. But, the soldiers started cursing and humiliating us," he said.
"They then attacked five of my guards. They beat up Luai Arafat, a guard, on his face and another one on his stomach with the end of their rifles. They then pushed my friend Dr Allam Jarrar to the ground. They beat me up heavily as I tried to help him."
Criminal and brutal
Al-Barghuthi condemned the attack as "brutal" and "criminal".
"They also prevented us from contacting anyone and forced us to stay outside for an hour and fifteen minutes in the cold," he said.
"The Israeli action is not only an assault, but also a torture. It is an example of what they practise against all the Palestinians all across our land," he added.
"What happened is an honour for me as I have been through what all our Palestinian people are facing"
He also pointed out the Israeli action comes in the context of a campaign against the presidential candidates.
"What happened is an honour for me as I have been through what all our Palestinian people are facing," al-Barghuthi said, adding that the soldiers' action reveal to the whole world what thousands of Palestinians face at checkpoints.