Gaza City (Palestinian Territories) (AFP) - Israeli air strikes on Gaza killed three Islamic Jihad militant group leaders early Tuesday and left 10 others dead, including several children, according to officials in the Hamas-controlled Palestinian territory.
Islamic Jihad vowed to "avenge" the deaths after the pre-dawn raid in which more than 40 Israeli jets hit targets for nearly two hours in the crowded coastal enclave from just after 2:00 am (Monday 2300 GMT).
The Gaza health ministry said four children were among those killed and 20 people were wounded, some of them in serious or critical condition, after the attacks which left buildings ablaze and reduced others to rubble.
Violence also flared later in the occupied West Bank when Israeli forces launched a raid in Nablus that left at least a dozen people suffering bullet wounds, according to Palestinian medics.
The Israeli army said that in its Gaza air strikes it had targeted three leaders of Islamic Jihad, which it considers a terrorist group, as well as its "weapon manufacturing sites".
Israel "achieved what we wanted to achieve" in the operation, said army spokesman Richard Hecht.Asked about child casualties, he said: "If there were some tragic deaths, we'll look into it."
Islamic Jihad confirmed three of its senior members were killed in Gaza.
It named them as Jihad Ghannam, secretary of the Al-Quds Brigades military council, Khalil al-Bahtini, commander of the military wing in northern Gaza, and Tareq Ezzedine, a military leader in the West Bank who operated from Gaza.
AFP photographers saw the body of a man identified as Ghannam in Rafah, in the south of the Gaza Strip, and also a boy's body in the morgue of Gaza City's Shifa hospital, where mourners had gathered.
Islamic Jihad vowed to retaliate, with spokesman Daoud Shehab warning that "the resistance considers that all cities and settlements in the Zionist (Israeli) depths will be under its fire".
Hecht said the military was "looking where this thing will develop", while instructing Israeli residents within 40 kilometres (25 miles) of the Gaza border to stay near bomb shelters until Wednesday evening.
'Avenge the leaders'
Israel last week traded air strikes on Gaza for rocket fire from the enclave, an exchange sparked by the death in Israeli custody of a Palestinian hunger striker with ties to Islamic Jihad, which ended with an Egypt-brokered truce.
Islamic Jihad charged on Tuesday that Israel had "scorned all the initiatives of mediators" and vowed it would "avenge the leaders" killed in the latest air strikes.
The Israeli military described Ghannan as "one of the most senior members" of Islamic Jihad who had coordinated weapons and money transfers with Hamas.
Bahtini was "responsible for the rocket fire toward Israel in the past month", Israel said.
And Ezzedine had been planning "multiple attacks against Israeli" civilians in the West Bank, it charged.
He was sentenced to 25 years in prison by Israel for his involvement in suicide attacks in the 2000s, before being freed in a 2011 prisoner exchange and transferred to Gaza, according to the army.
An Islamic Jihad source told AFP that Ezzedine was part of a delegation from the group that had been due to travel to Cairo for a meeting Thursday, which had now been cancelled.
'Treacherous operation'
The army later Tuesday said its troops had entered Nablus in the West Bank, which has been occupied by Israel since the Six-Day War of 1967, with residents telling AFP they heard explosions during the raid.
The Palestinian Red Crescent Society said its medics treated 145 injuries in Nablus, including a dozen people who were shot with live fire and many more who suffered tear gas inhalation.
Hamas chief Ismail Haniyeh said in a statement on the Gaza attacks that "assassinating the leadership in a treacherous operation will not bring security to the occupier, but instead greater resistance".
The militant group's spokesman, Hazem Qassem, warned that Israel "bears responsibility for the repercussions of this escalation".
Israel and Gaza militants have fought multiple wars since Hamas took control of the enclave in 2007.
A three-day conflict in Gaza last August left 49 Palestinians and no Israelis dead, with Cairo playing a key role in securing a ceasefire.
Tuesday's deaths bring to 121 the number of Palestinians killed in the Israeli-Palestinian conflict so far this year.
Nineteen Israelis, one Ukrainian and one Italian have been killed over the same period, according to an AFP count based on official sources from the two sides.
