Most of the victims were shot dead by Israeli military in Jenin in the northern West Bank, the Palestinian Ministry of Health said.
The violence is reported to have started when Israeli soldiers entered a Palestinian refugee camp in Jenin on Thursday morning.
Among the dead is a 60-year-old woman, according to Palestinian authorities who state that another ten people have been injured.
Palestinian President Mahmoud Abbas has announced three days of national mourning, writes the Palestinian news agency Wafa.
"Stop terrorist attack"
From the Palestinian side, it is also stated that tear gas has been fired into a hospital in Jenin - accusations that Israel's defense denies.
- No one deliberately shoots tear gas at a hospital.
But the operation took place not far from a hospital and it is possible that tear gas may have entered through an open window, an Israeli army spokesperson told the AFP news agency.
Israel's army claims that during the morning it carried out an operation to arrest militant Islamists and stop a terrorist attack in Jenin, according to The Jerusalem Post, and that the soldiers in question fired their weapons only when they were attacked.
The army has now been prepared for increased violence in the city, the newspaper writes.
No Israeli soldiers were reported injured.
Worst year since 2004
The recent past has been unusually violent in the occupied West Bank.
On Wednesday, a 20-year-old Palestinian from the refugee camp in Jenin was shot dead after, according to Israeli media, stabbing an Israeli soldier.
A 17-year-old Palestinian was also killed yesterday after pointing a mock weapon at Israeli police officers, writes Haaretz newspaper.
The violence comes in light of the entry into force of Israel's most right-wing government ever.
The far-right coalition, which has been described as more religious and nationalist than ever before, has promised to crack down on the Palestinians and expand illegal settlements in the West Bank.