Israeli tanks and troops raided southern Gaza on Friday in response to increasing Palestinian mortar attacks, killing at least six Palestinians and prompting hundreds to flee their homes.
Meanwhile, at least five other Palestinians were trapped in what was described as an arms-smuggling tunnel that collapsed as it was being dug under an army-controlled security strip between the Gaza town of Rafah and nearby Egypt, witnesses said.
Palestinian ambulances and rescue crews given clearance by Israeli forces rushed to the scene. Officials said earlier accounts that two men had been extracted from the tunnel were incorrect, citing poor communications in the area.
At least six Palestinians were killed and 24 wounded in today's army raid into Khan Younis, Gaza's second largest city and a hotbed of militants who frequently pepper nearby Jewish settlements with mortar and rocket fire.
Four of the dead were militants and two were civilian bystanders, local medics and witnesses said.
The raid included a helicopter missile strike intended to wipe out launching points for mortars and rockets that are fired daily at nearby Jewish settlements in the crowded Gaza Strip.
The incursion unfolded hours after Israeli Prime Minister Mr Ariel Sharon told a high-profile security conference that there was a unique chance for Middle East peace with new Palestinian leaders following the death of Yasser Arafat.
Qassam rockets fired by Hamas militants from northern Gaza today landed in Israeli territory near the town of Sderot but caused no casualties. It was the first rocket launch from north Gaza since a massive army raid there in October.