Israeli troops shot dead three Palestinians overnight near the Jewish settlement of Elai Sinai in the northern Gaza Strip.
The Israeli army said troops fired when the men approached a security fence, and assault rifles were later found next to the bodies.
And there were further signs of in-fighting in the Palestinian Territories today when a policeman hurled hand grenades into a Gaza jail cell holding prisoners accused of collaborating with Israel, wounding seven inmates today.
The assault inside a main Palestinian security compound in Gaza City appeared to be an attempt to kill a veteran Hamas member convicted of helping Israeli intelligence services kill fellow Islamic militants, Palestinian security sources said.
The incident followed a warning to Palestinian President Yasser Arafat from former security chief Mohammed Dahlan, still a powerful figure in Gaza, of further internal unrest unless anti-corruption reforms are implemented.
"It is time for Yasser Arafat to punish the corrupt," Mr Dahlan told al-Arabiya satellite channel last night.
Palestinian areas have been rocked by upheaval in recent weeks, including kidnappings, street protests and gun battles between militants and security forces, in the biggest internal challenge to Mr Arafat since he returned from exile a decade ago.
The turmoil is seen as part of a power struggle between Mr Arafat's old guard and a younger generation jockeying for position before Israeli Prime Minister Ariel Sharon carries out a planned withdrawal from occupied areas of Gaza in 2005.