Michael O'Flaherty, the Council's commissioner for human rights, said member states should do "their utmost to prevent and address violations of international human rights" in the conflict.

"This includes applying existing legal standards to ensure that arms transfers are not authorised where there is a risk that they may be used to commit human rights violations," he said, in a statement.

It was also "essential to intensify efforts to provide relief to those affected by the conflict, by supporting efforts to ensure unhindered access for humanitarian assistance and by pressing for the immediate release of hostages", O'Flaherty said.

The call by the Council -- a human rights organisation representing 46 states -- comes shortly after Germany said it would halt delivery to Israel of some weapons that could be used in Gaza as part of Israeli plans to take control of Gaza City.

O'Flaherty said the Council had taken note of this and other government initiatives, and also of contributions by some national human rights structures in raising awareness.

"However, more needs to be done, and quickly," he said.

Several world leaders have condemned Israel's decision to widen the Gaza war.

But Prime Minister Benjamin Netanyahu said Sunday that the plan to target the remaining Hamas strongholds in Gaza was "the best way to end the war".