Witnesses said Israeli soldiers raided a neighborhood in the center of Qalqiliya and opened fire at 28-year-old Samir Abd al-Rahman Yasin, leaving him to bleed to death.
The soldiers shot Yasin "in cold blood," locals said.
A statement issued by the Israeli army said that during a "successful overnight ambush" that was "preplanned," a Palestinian who opened fire at Israeli soldiers was killed.
"The soldiers retaliated towards the source of fire," the statement said.
According to the statement, the "assailant" whom Israeli soldiers killed was "a known gunman" who had exchanged fire with Israeli forces before.
"A gun and ammunition were later found at the scene," the statement said.
Yasin was a member of the Palestinian security forces.
A report by the Israeli news site Ynet said that no Israeli soldiers were injured.
Additionally, late Wednesday, one Palestinian was killed and at least six others were injured after Israeli forces raided Jenin refugee camp and entered the house of a Hamas leader and prisoner.
Locals said undercover Israeli forces arrived at Abu al-Hayja’s home in a car with Palestinian license plates before clashing with Palestinians who noticed them.
Palestinians threw an improvised explosive device at the Israeli forces who called for reinforcements.
Around 25 military vehicles arrived in the camp and fired live ammunition at Palestinians, injuring three people critically. Two people were shot in the stomach and one in the head.
One person died on the way to hospital, an Israeli army spokeswoman told Ma'an. She said military medics were treating the injured Palestinians after the incident.
Witnesses said Israeli forces were refusing to allow ambulances near other injured people.
The spokeswoman said Palestinians fired at army personnel who "retaliated in self-defense."
Army spokesman Peter Lerner said that "operations like this are aimed at preventing the terrorists from reaching our towns and abducting our civilians and attacking Israeli commuters on the road."