Explosions and gunfire sounded as troops entered the city of Nablus on Wednesday morning, sparking armed clashes with Palestinian gunmen.
The Israeli military said it killed three wanted militants holed up inside a house who refused to surrender.
Several of those killed outside were civilians, including two elderly men.
The Palestinian health ministry said 72-year-old man was one of them. Video footage purportedly showed his body in a street next to bags of bread, in what is usually a busy market area.
The Ministry also said that 61-year-old man and a 16-year-old boy were also shot dead.
Another elderly man, 66, who suffered from tear-gas inhalation, died in hospital on Wednesday evening. Six members of the Lions’ Den and other militant groups were killed during the raid.
What makes this raid more significant is the huge numbers wounded, with the Palestinian health ministry saying more than 80 people have suffered bullet wounds. Five different hospitals in Nablus are currently treating them.
Senior Palestinian official condemned the incident as he termed it as a “massacre”. Spokesman for Palestinian President said he held Israel’s government responsible for pushing the region towards tension and an explosion.
The raid lasted four hours and took place in the middle of morning, when the narrow streets of the old city are usually packed with families and people shopping.
The Israel Defense Forces said it “upgraded” its operation after forces were shot at by Palestinian gunmen. Its troops fired shoulder-launched missiles at the building where the wanted militants were hiding, which caused it to partially collapse.
But Palestinian videos posted on social media also show young men in the street, who appear unarmed, apparently being fired at while running away, with one falling to the ground as gunshots are heard. The IDF described the footage as “problematic” and said it was being reviewed.
Two of the militants in the encircled building were Muhammad Junaidi, a commander in Palestinian Islamic Jihad, and another senior militant figure, Hussam Isleem.
The IDF said they and the third militant, Walid Dkhail, were suspected of carrying out previous shooting attacks, including one in the West Bank last October that killed an Israeli soldier, and of planning more attacks in the near future. Two other suspects were arrested in Nablus last week.
During the raid, Isleem recorded a WhatsApp audio message that was shared on social media, saying: “We’re in trouble, but we won’t surrender ourselves. We won’t hand over our weapons. I’ll die as a martyr. Keep carrying weapons after us.”
Isleem’s house had been raided by Israeli forces earlier this month and his family interrogated. His father told Palestinian media afterwards that forces told him his son should hand himself in or he would be killed.
Israel has targeted parts of both cities in waves of search, arrest and intelligence-gathering raids, saying it is trying to stem the spate of deadly attacks against Israelis.
So far this year, more than 60 Palestinians – including militants and civilians – have been killed, while 11 people have been killed in Palestinian attacks targeting Israelis.
Wednesday’s deadly raid in Nablus is a further sign that recent attempts led by the US to ease tensions are failing.