The latest fatality came after Israeli forces opened fire on a group of mourners marching on Saturday at the funeral of three Palestinians killed earlier in the day by Israeli fire, Aljazeera's correspondent reported.
Witnesses said Muhammad al-Masri, a relative of one of those being buried, was shot in the head and seriously wounded during the funeral procession. He died shortly afterwards from his wounds.
Those attending the funeral said occupation soldiers opened fire without provocation from a distance of 200 metres.
Earlier, soldiers fired on Palestinians throwing stones at an Israeli "patrol", killing three of them.
Amjad Bilal al-Masri, 15, was killed by two bullets to the chest, fired by a sniper, as he hurled stones from a rooftop.
An hour later, Amir Arafat, 18, and Rawahi Shuman, 25, were pronounced dead on arrival in hospital after coming under Israeli fire.
Witnesses said the two men were hit in the chest when troops fired live bullets to disperse stone-throwers.
An Israeli army spokesman said the soldiers had hit two Palestinians, one of them "armed" and the other preparing to throw a petrol bomb.
Nablus has been under total Israeli curfew for nine days, according to Aljazeera's correspondent there, who added, Israeli forces began their raids into the city 14 days ago.
Occupation troops have invaded
Nablus and the Balata camp
The Palestinian Red Crescent Society says its ambulance crews have been denied access to al-Qarun area of the city.
Locals living in the old city quarters of Nablus said occupation soldiers were searching houses and making arrests.
"The soldiers have been making many arrests and they have been using explosive devices to blast their way into the houses," said the man.
Another local who only wanted to be identified by his first name told Aljazeera.net occupation troops had been opening fire in the streets of the old city.
"The soldiers are shooting everywhere and they have occupied at least 10 houses in Nablus. They only left the city a few days ago and now they are back with more tanks and bullets" said Hussein.
Meanwhile, in the nearby Balata refugee camp, occupation troops have re-invaded the camp with scores of soldiers inside the refugee camp and four bulldozers outside one of the entrances to Balata.
"The soldiers returned to Balata on Friday night, they have been shooting inside the camp and they have placed us under curfew. I can hear ambulance sirens - they seem to be heading towards the city of Nablus," said a Balata local.
Occupation soldiers demolished historical buildings in al-Qarun, in the Old City, claiming they were looking for tunnels where resistance fighters take refuge.
Huge Israeli bulldozers demolished the buildings, witnesses told Aljazeera. Explosions were later heard in several areas, they added.
Israeli occupation soldiers have also invaded the northern West Bank City of Jenin, hours after the Israeli military announced it had pulled troops out of the city.
A Palestinian in Jenin climbs an
Israeli amoured personnel carrier
Media reports stated occupation troops had dismantled roadblocks and tanks had been withdrawn, opening up routes between the city's eight entrances and surrounding villages.
However, residents painted a different picture.
"They have been moving their soldiers and tanks into Jenin all night, the number of troops in the city has increased.
"The Israelis are lying when they say their soldiers are leaving the area, this is propaganda," said a local man who did not want to be named for fear of reprisals from occupation troops.
Palestinian officials in Jenin city described the Israeli decision to lift the curfew on the city as a "false announcement" to mislead the world.
"The Israelis are lying when they say their soldiers are leaving the area, this is propaganda"
Resident of Jenin
But an Israeli military spokesman denied the invasion of the city was fresh, saying soldiers were "conducting routine searches". He failed to specify what the occupation troops were looking for.
"On Thursday we decided to remove the encirclement around the city but this doesn't mean that the force will not go back in to carry out patrols or conduct searches," he told news agencies.
Israel has repeatedly invaded Jenin since 3 April 2002 when a major assault on the town's refugee camp killed 52 Palestinians and cost the Israelis 23 soldiers.
Meanwhile Israeli occupation soldiers imposed a curfew on the town of Bait Ummar, near the West Bank city of al-Khalil (Hebron).
Aljazeera's correspondent in the town reported occupation soldiers had carried out house to house searches, demolishing a house.
It was unclear what the soldiers were looking for, he added.
On Friday, occupation soldiers wounded five Palestinians in Gaza, two in the city of Ram Allah and one Palestinian in