Men, women and children gathered at the city's main football stadium to pay tribute to Jamal Mansour and Jamal Salim, killed with another six Palestinians in an Israeli attack on Thursday.
The crowd waved portraits of several resistance fighters killed over the past 34 months since the start of the intifada, and carried the green flags of Islamic group Hamas.
During the rally a Hamas leader threatenined to end the three-month suspension of anti-Israeli attacks declared by the resistance group in late June.
"Hamas today is studying its position regarding the truce because Israel is not responsive and continues to commit crimes against Palestinians," said Adnan Asfour.
"After it (the truce) is over if Israel goes on with its violence, there will be a huge response from Hamas" -- Hamas leader Adnan Asfour
"A month went by after we announced the truce. After (it is over) if Israel goes on with its violence, there will be a huge response from Hamas," he added.
The crowd were then treated to a short play depitcing a Palestinian agricultural worker being ousted from his land and beaten up by Israeli soldiers to allow for the construction of the controversial security wall.
The barrier, which incorporates a network of earthworks, trenches and patrol roads, will eventually snake 900 km along the West Bank.
It does not run by Nablus, but has taken the shape of a fully-fledged wall in the nearby West Bank towns of Qalaqilya and Tulkarem.
And it has already left large swathes of Palestinian territory on the Israeli side and bisected a whole string of Palestinian communities throughout the West Bank.
Israel say the wall is necessary to protect its citizens from Palestinian attacks.