The Palestinian Ministry of Health confirmed the death overnight of Mustafa Nidal Qassem, 17, wounded on Monday by Israeli army gunfire.
The Red Crescent said the body of another Palestinian was found on Tuesday morning in the fields, reported the Palestinian news agency WAFA.
Eight Palestinians ranging in age between 16 and 23 years were killed on Monday and over 100 were wounded, including 20 in critical condition, when hundreds of Israeli soldiers backed by warplanes, drones and tanks attacked Jenin.
The raid, launched under Prime Minister Benjamin Netanyahu's hard-right government was the biggest in the West Bank for years.
Since the start of the operation in the early hours of Monday about 3,000 residents, have been forced by Israel occupation forces to leave their homes, deputy governor of Jenin, Kamal Abu al-Roub told AFP, adding arrangements were being made to house them in schools and other shelters in the city of Jenin.
Residents said Israeli soldiers broke into their homes and told them to leave the camp because they are going to shell it. In some cases, the soldiers threw tear gas grenades at the fleeing civilians, WAFA reported.
Firefights and explosions rocked the city and adjacent refugee camp, a stronghold home to about 18,000 people, as Palestinians threw rocks at soldiers and smoke from blasts and burning barricades darkened the sky, an AFP correspondent said.
"There is bombing from the air and an invasion on the ground," said Mahmoud al-Saadi, director of the Palestinian Red Crescent in Jenin.
"Several houses and sites have been bombed... smoke is rising from everywhere."
Israel killed seven Palestinians two weeks ago which saw the rare use of helicopter missile fire.
The Palestinian foreign ministry called the escalation "an open war against the people of Jenin".
Israeli occupation army spokesman Daniel Hagari told reporters that Israeli troops did "not intend to stay in the camp", but "we are getting ready for the more severe situation" of prolonged fighting.
Jenin resident Badr Shagoul told AFP: "I saw them taking bulldozers into the camp, they were destroying buildings ... These were people's homes."
At a hospital morgue some bodies were covered in blankets and others were heavily bandaged, an AFP correspondent said, adding that the fighting continued into the late evening.
"In the last five years, this is the worst raid," nurse Qasem Benighader said, noting "many" patients with bullet wounds and injuries from explosives.
Israel had already stepped up operations in the northern occupied West Bank, which has seen a recent spate of attacks on Israelis as well as Israeli settler violence targeting Palestinians.
Jenin camp resident Mahmoud Hawashin called the situation "catastrophic", and predicted that "if there is more Palestinian blood shed, there will be more Israeli blood shed."
UN Secretary-General Antonio Guterres is "deeply concerned" about the violence, and called for the respect of international humanitarian law, a spokesman said in a statement.
'Escalating campaigns'
The Palestinian group Islamic Jihad said, "all options are open to strike the enemy in response to its aggression in Jenin".
The United States said ally Israel had a right to "defend its people against... terrorist groups" but called for the protection of civilians.
The Arab League said it will convene an emergency meeting Tuesday to discuss "an Arab mobilisation to counter the Israeli attack on Jenin".
Neighbouring Jordan called the raid "a clear violation of international humanitarian law", while the United Arab Emirates urged "the immediate halt of repeated and escalating campaigns against the Palestinian people".
Egypt strongly condemned the Israeli forces' attack and warned against the risks of the ongoing Israeli escalation against the Palestinians.
Earlier on Monday the Israeli occupation army said it had struck a "joint operations centre" of a group called the Jenin Brigade, a weapons depot, an "observation and reconnaissance" site and a hideout for alleged attackers of Israeli targets.
Occupation army spokesman Richard Hecht said troops were after "specific targets", adding the operation had no defined timeline.
Israeli-Palestinian violence has worsened since last year, and escalated further under the Netanyahu coalition government that includes extreme-right allies.
The Jenin area is nominally controlled by Palestinian Authority, which has partial administrative control in the West Bank.
In a separate incident, Israeli fire killed a Palestinian youth near the West Bank city of Ramallah, the Palestinian health ministry said.
Settlements
Israel has occupied the West Bank and Jerusalem since the Six-Day War of 1967. The territory is now home to around 700,000 Israelis in settlements considered illegal under international law.
The Palestinians, who seek their own independent state, want Israel to withdraw from all land it seized in 1967 and to dismantle all Israeli settlements.
Netanyahu, however, has pledged to "strengthen settlements" and expressed no interest in reviving peace talks, moribund since 2014.
After last month's Jenin raid, four Israelis were killed by two Palestinian gunmen -- who were shot dead -- near the West Bank settlement of Eli.
That same week, Israel said a drone strike killed three other Palestinians in the West Bank.
At least 185 Palestinians have been killed this year, according to an AFP tally compiled from official sources.
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