Three people were killed and dozens wounded on Tuesday, the Palestinian health ministry said, as Israeli forces raided a house in the occupied West Bank city of Nablus.
The Israeli military said a senior commander was among the dead.
The latest violence comes two days after deadly fighting between Israel and Islamic Jihad in the coastal enclave of Gaza was halted by a truce.
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In the old city of Nablus, an AFP correspondent reported Palestinians trading gunfire with Israeli security forces.
At least 40 Palestinians were wounded, four of them in serious condition, according to the Palestinian health ministry.
Palestinian demonstrators clash with the Israeli army while forces carry out an operation in Nablus on Tuesday. AP
"The terrorist Ibrahim Al Nabulsi was killed in the city of Nablus," the Israeli army said in a statement, adding that "another terrorist who was staying in the house" also died.
Israeli forces said they launched a shoulder-fired missile at the house and detained four suspects in the raid.
Nabulsi was a commander of the Al Aqsa Martyrs' Brigade, one of the main groups present in the West Bank operating under the ruling Fatah party.
Hundreds of people gathered outside the Nablus hospital where Nabulsi was brought by a dozen gunmen, an AFP correspondent said.
Heavy gunfire was heard as dozens of Israeli military vehicles brought traffic in one of the West Bank's largest cities to a standstill.
Clashes with the Israeli army also broke out in other parts of the city, as Palestinians hurled stones at the troops.
"A violent clash developed with dozens of rioters who threw stones and threw explosives at the forces, who responded by means of crowd dispersal and shooting. Several injuries were confirmed," the army said.
Palestinian protesters hurl rocks at Israeli security forces vehicles during their raid in the old town of Nablus. AFP
"All the forces have left the city, there are no casualties to our forces," it added.
Israeli security forces have conducted near-daily operations in the West Bank in recent months, focusing on the Islamic Jihad group.
Deadly Gaza fighting
On Friday, Israel launched what it called a "pre-emptive" aerial and artillery bombardment of Islamic Jihad positions in the Gaza Strip, leading group in the coastal enclave to fire more than a thousand rockets in retaliation, according to the army.
An Egypt-brokered ceasefire reached on Sunday ended three days of intense fighting that killed 46 Palestinians, 16 of them children, and wounded 360, according to Gaza's health ministry.
Israeli Prime Minister Yair Lapid spoke by telephone with Egyptian President Abdel Fattah Al Sisi on Monday, with the premier "expressing his appreciation" for Cairo's mediation.
A Palestinian demonstrator clashes with the Israeli army in the West Bank town of Nablus, on Tuesday. AP
Israel insists that some of the children and other civilians counted in the Palestinian toll were killed by Islamic Jihad rockets that fell short or misfired.
Lapid said on Monday that the bombardment had "landed a devastating blow to the enemy", and that the "entire senior military command of Islamic Jihad in Gaza was successfully targeted."
Islamic Jihad said 12 of its members had been killed, including commanders Taysir al-Jabari and Khaled Mansour.
Mohammad Al Hindi, a senior member of the group, said the ceasefire deal "contains Egypt's commitment to work towards the release of two prisoners".
They were named as Bassem al-Saadi, a senior figure in the group's political wing who was arrested in the West Bank early last week, and Khalil Awawdeh, a group also in Israeli custody.
Agence France-Presse