The United States on Sunday urged Israel to exercise restraint toward rocket attacks by the Islamic Resistance Movement (Hamas) while warning the Palestinian militants against firing rockets at Israeli targets.

"We remain concerned about the violence and urge all sides to demonstrate appropriate restraint," National Security Council spokesman Gordon Johndroe said in Crawford, Texas where President George W. Bush is spending his weekend at his ranch.

However, Johndroe noted, "Hamas needs to stop firing rockets into Israel."

The spokesman made the remarks hours after Israeli Prime Minister Ehud Olmert warned in Jerusalem that Israel would step up it efforts against Hamas as long as it continues to launch Qassam rockets to Israel.

At least 125 Qassam rockets have landed in western Negev area, Israel in the past five days, the Israel army said.

In response to continuing rocket fire from Palestinian gunmen, Israel has waged air strikes against militant targets in Gaza for five days, having reportedly killed four civilians and 19 Hamas militants.

Source: Xinhua