GENEVA, Switzerland: Switzerland has said Israel is violating international law in its Gaza offensive by inflicting heavy destruction and endangering civilians in acts of collective punishment banned under the Geneva Conventions.

In a statement, it said Israel's destruction last week of the main Gaza electricity power station and its attack on the office of the Palestinian prime minister were unjustified.

Israel has used tanks, troops, gunboats and aircraft to attack the Gaza area over the past week to press a group, holding an Israeli soldier, to free him.

"A number of actions by the Israeli defense forces in their offensive against the Gaza Strip have violated the principle of proportionality and are to be seen as forms of collective punishment, which is forbidden," the Swiss Foreign Ministry said.

Switzerland also called for the "rapid release" of the captive Israeli soldier, Cpl. Gilad Shalit. But it said Israel had an obligation "to respect international humanitarian law in the measures it undertakes to liberate the captured soldier."