The latest deaths were of two Palestinian children who were killed by an Israeli tank shell in the central Gaza Strip early on Friday, Palestinian hospital and security sources said.
The sources said seven-year-old Ahmad al-Smari and his cousin, Muhammad al-Smari, eight, were killed when an Israeli tank shell slammed into their house near the southern city of Khan Yunus, shredding their bodies.
The children's deaths bring the number of people killed since the beginning of the Palestinian intifada, or uprising, in September 2000 to 4556, including 3522 Palestinians and 960 Israelis.
Late on Thursday, three other Palestinians were killed near the al-Burij refugee camp by Israeli tank fire, Palestinian security sources said. There were no further details and their identities were not immediately known.
In other developments, Israeli aviation violated Lebanese airspace over the south of the country several times on Thursday, the United Nations office in Beirut reported.
"As of 3.45pm (1345 GMT), eight violations, involving 11 aircraft and three drones, were recorded," said a UN statement, adding that "there have been no reports of any ensuing anti-aircraft fire across the Blue Line".
The statement said Staffan de Mistura, the personal representative in Lebanon of UN Secretary-General Kofi Annan, was concerned by the violations of the Blue Line drawn between the two countries after Israeli forces withdrew from southern Lebanon in 2000.