GAZA, Aug 8: Israel fired five helicopter missiles into the fringes of Rafah refugee camp in the Gaza Strip on Sunday but there was no immediate word of casualties.

They said one missile hit a power transformer, causing a power blackout in the large urban camp of 80,000 people, also a stronghold of Palestinian militants.

The others landed nearby, in an area abutting the border with Egypt where Israeli forces had earlier razed housing in raids against militant groups.

Medics said ambulances were trying to get to the area where the missiles crashed to check for possible casualties but darkness from the blackout was hindering their efforts.

Israeli military sources confirmed missiles were fired and said it was a preventative measure to repulse militants preparing to attack an army position. Israel has carried out many aerial missile strikes and ground offensives in Gaza and the West Bank in rolling campaigns to quell Palestinians in revolt since 2000.

Violence has surged in Gaza as militants seek to portray Israel's plan to evacuate Jewish settlers next year as a victory with determined to prevent that by smashing Palestinian armed factions first.

Palestinian sources said an Israeli helicopter fired five rockets that damaged a local power network and caused a blackout near Rafah.

An Israeli military source said the rockets were "warning shots on open territory to prevent terrorist operations". The home of a Palestinian militant accused of planning several suicide attacks was demolished in Bethlehem. -Agencies