An 75-year-old shepherd was among three Palestinians who died on Tuesday in fresh Middle East violence.
Troops have been mounting arrest operations
An Israeli army spokeswoman said the shepherd was spotted riding a donkey in "an area in which Palestinian movement is prohibited", prompting troops to open fire.
In the West Bank, two young men also died from Israeli gunfire in separate incidents.
The killings come a day after the US took the rare step of criticising Israel over the number of civilian casualties in army operations, following the deaths of eight Palestinians.
Abdallah al-Ashab, who often took his flock to graze near the Jewish settlement of Netzarim, just south of Gaza City, was hit in the neck, Palestinian doctors at the city's main hospital said.
The Israeli army was unable to say whether warning shots had been fired, but said he had entered a restricted zone. They said the incident would be investigated.
Meanwhile, a teenager was killed during a raid on an internet cafe in Jenin by undercover Israeli troops.
The Israeli army said Hissam Mahmoud Amr belonged to the militant Islamic Jihad group and had thrown a petrol bomb at the troops.
Some witnesses said he was unarmed and not a militant, although others said he was a member of Islamic Jihad.
Six Palestinians and two Israeli border police were said to have been injured.
And later on Tuesday evening, a 25-year-old man was shot dead on Tuesday evening in a stone-throwing incident in the West Bank town of Tulkarm.
Witnesses said he had been a bystander; the Israeli army said he was armed.
In other incidents:
Jewish settlers travelling in a car shot at stone-throwers just outside Nablus in the West Bank, seriously wounding a 14-year-old Palestinian boy, medics and witnesses said. Israeli police said they were investigating.
A 19-year-old Israeli woman was reportedly stabbed in the stomach by a Palestinian as she waited at a bus stop in the southern Negev desert town of Arad. An Israeli police spokesman said the man had been caught.
Two Israelis were indicted on charges of attempted murder of a Palestinian labourer they are accused of running over on Saturday near a Gaza checkpoint, the Israeli daily Haaretz reported.
Army operations on Tuesday followed similar activities by Israeli troops in the Gaza Strip on Monday.
A raid on the Bureij refugee camp on Monday which left eight Palestinians dead, including a pregnant woman, drew rare criticism from the United States.
"We continue to be seriously concerned about civilian casualties," said State Department spokesman Richard Boucher.
"We have urged the Israeli Government to take appropriate caution to prevent the death or injury of innocent civilians and damage to civilian humanitarian structures."
The Gaza raid targeted Hamas
Palestinian hospital officials said the pregnant 33-year-old was killed by falling masonry when the army blew up a house during the raid.
The US, Israel's greatest financial sponsor, has been seeking a period of quiet in the West Bank and Gaza as it tries to win support from Arab and Muslim countries for a war against Iraq.
Palestinians however see Israel's latest offensive as an effort to deal militant groups a fatal blow before any US campaign.