Five Palestinian men have been killed by Israeli forces in four separate incidents in the occupied West Bank, Palestinian and Israeli officials say.
Israel's military said the fourth was shot after he rammed his car into a soldier, seriously injuring her.
The fifth reportedly died after fresh clashes near Ramallah in the evening.
The UN has warned that the Israeli-Palestinian conflict is "again reaching a boiling point" after an escalation violence in the West Bank and Israel.
Israeli forces are carrying out search-and-arrest raids almost every night in the West Bank, where at least 140 Palestinians have been killed this year, most by Israeli fire. More than 30 Israelis have also been killed amid a spate of gun and knife attacks by Palestinians.
Jawad Rimawi, 22, and Thafer Rimawi, 21, who were students at Birzeit University, were killed early on Tuesday about 16km (10 miles) north-west of Ramallah.
Palestinian sources said the brothers had visited a relative in the village of Beit Rima as Israeli forces carried out an operation in the area.
As the forces withdrew, confrontations broke out with dozens of young Palestinians, who threw stones and petrol bombs, the sources added.
The Palestinian health ministry said the brothers were shot and taken to a local hospital, where they died.
The Israel Defense Forces (IDF) said that a "riot was instigated by a number of suspects" during a "routine" overnight activity.
"The suspects hurled rocks and Molotov cocktails toward the soldiers, who responded with riot dispersal means and live fire," it added.
Mufeed Ikhlil, a 44-year-old father of six, was shot in the head by Israeli troops during overnight clashes with stone-throwing Palestinians in Beit Ummar, about 10km north of Hebron, the Palestinian health ministry said. He died in hospital.
Eight other Palestinians were shot and injured, according to the ministry.
The IDF said two army jeeps got stuck in Beit Ummar due to "technical malfunctions" during a patrol.
The troops in the vehicles were attacked by Palestinian "rioters" who "hurled rocks and improvised explosive devices at the soldiers", it added.
West Bank-based Palestinian Authority Prime Minister Mohammed Shtayyeh called the three killings an "ugly crime", while the spokesman of President Mahmoud Abbas warned that "the daily killing of Palestinians is a declaration of war".
A spokesman for the militant group Hamas, which controls the Gaza Strip, said Israel's "escalation of its crimes and terrorism will be met with an escalation of resistance".
Later on Tuesday, the IDF said a man rammed one of its soldiers with a vehicle near Kokhav Yaakov, a Jewish settlement about 2km south-east of Ramallah.
"Israel police forces in the area pursued the assailant and neutralised him," it added.
Israel's ambulance service said the 20-year-old soldier was in a serious condition at Jerusalem's Shaare Zedek Medical Center.
The hospital confirmed that the driver was killed. Israeli media identified him as Rani Abu Ali, a 45-year-old man from Beitunia.
CCTV footage apparently from the incident show an SUV turning around in a car park and then accelerating directly towards a soldier walking on a pavement.
On Tuesday evening, another Palestinian man was shot dead by Israeli forces during clashes in al-Mughayyir, a village about 16km north-east of Ramallah, Palestinian health officials said.
The official Wafa news agency cited a local Palestinian activist as saying that troops opened fire when a group of young men attempted to block their entry to the village, hitting one of them with a live round and several others with rubber-coated bullets.
Raed Ghazi Naassan was wounded in the chest and died in hospital, Wafa said.
There was no immediate comment from the IDF.
Tuesday's incidents come five days after co-ordinated bomb attacks at bus stops on the outskirts of Jerusalem killed a 15-year-old Israeli-Canadian boy and a 50-year-old Israeli man. Thirteen other people were wounded.
So far, no group has claimed it was behind the twin bombings, which were praised by Palestinian militants.