Warplanes dropped thousands of fliers over the battered Gaza Strip on Friday, urging Palestinians to report to Israeli authorities the location of Hamas forces, witnesses said.

"Rocket launchers and terrorist elements constitute a risk for you and your families," said the flier, written in Arabic.

The tracts provide a telephone number and an e-mail address for anyone wishing to denounce the "activities of the terrorist elements."

"For your security we ask you to be extremely discreet when contacting us," the text says.

Israel launched its deadly assault on Gaza on Dec. 27. At least 420 people have been killed as sporadic air strikes ravage the strip for the seventh day in a row.

(AFP and Alarabiya.net)