Clashes with Israeli troops raiding the northern West Bank town of Nablus on Wednesday, also left up to 30 people injured. A 14-year old Palestinian boy is in a serious condition after being shot in the head.
The occupation forces, backed by tanks and helicopters, surrounded a building in the town where wanted resistance fighters were believed to have been hiding, according to Aljazeera's correspondent in Nablus Hasan al-Titi.
The building came under heavy artillery fire.
The young girl, Mariam al-Nakhlah, was hit by gunfire when she went out of her house as an ambulance arrived, medics and relatives said.
"She was watching the ambulances taking away the bodies when soldiers posted on the roof of a house shot at her, hitting her in the face," the girl's grandmother, Muyasar al-Nakhlah, said.
Among the dead were members of al-Aqsa Martyrs Brigades and the Democratic Front for the Liberation of Palestine.
Aljazeera's correspondent said medics could not immediately access the area to identify the bodies. However, Israeli military sources revealed the names of three of the dead as Nadir al-Aswad, Hani al-Aqqad and Mulham Abu Jamila.
Israeli forces began demolishing the building following the assault.
Israel's punitive tactics have left
many Palestinians homeless
According to Aljazeera's correspondent, the Israeli military raid is continuing and residents of the town have been ordered out of their homes while their residences are searched.
Israeli snipers are stationed on rooftops and at windows of buildings surrounding the site where the activists were killed.
Aljazeera's media crew has been prevented from approaching the site, al-Titi said.
An Israeli army spokesman, quoted in Israeli newspapers, said he would not comment on casualties but confirmed that "operations" were under way in the city.
The town has now been closed off.
Meanwhile, four Palestinians were killed when an Israeli special force attacked a mechanical workshop in an industrial zone outside the West Bank town of Jenin.
Their identities' were not immediately known.
The assault by Israeli special forces backed by helicopters brought to 10 the toll in back-to-back military raids in Jenin and Nablus in the bloodiest day in the West Bank in months.