Palestinian President Mahmoud Abbas on Wednesday called Israel's attacks on civilian infrastructure "collective punishment and a crime against humanity".

Israeli aircraft hit three bridges and a power station, leaving the coastal country blacked-out, after an assault aimed at freeing 19-year-old corporal Gilad Shalit was launched. The offensive started three days after the soldier was kidnapped by Palestinian gunmen from a military border post.

Israeli Prime Minister Ehud Olmert said on Wednesday that the operation would continue over the coming days if the abducted soldier is not released.

Speaking in Occupied Jerusalem Olmert said, "We have no intention of recapturing the Gaza Strip. We have no intention of staying there. We have a central goal and that is to bring Gilad home."

"We won't hesitate to carry out extreme action to bring Gilad back to his family," he added.

A legislator from the governing Hamas movement, Mushir Al Masri, said Olmert's "adventurism" was "putting the missing soldier at risk".

Palestinian President Mahmoud Abbas said he has no knowledge of the soldier's location, but urged the militants to release him.

Meanwhile, Egypt has?called on?Hamas' Syrian leader, Khaled Mashaal, to help facilitate the release of the soldier, officials said on Tuesday.

A Hamas representative in Lebanon, who is close to Mashaal, denied Mashaal had organised the attack and suggested that Israel think twice about assassinating him, which they threatened earlier.