Tel Aviv/Gaza/Cairo - Israel continued its offensive in the Gaza Strip Saturday, killing at least 36 Palestinians, while the military threatened to expand its operations.

Residents in the enclave said they received leaflets, dropped from the air, warning them the military would scale up the campaign.

The military "will continue to target tunnels, weapon storage facilities and terror operatives with growing intensity throughout the Gaza Strip," read the leaflet, signed by the military, warning civilians to take precautions.

Warsaw  - Some 500 people marched in support of Gaza at a demonstration in Warsaw on Saturday, while a smaller group gathered for a demonstration backing Israel.

The pro-Palestinian protesters carried photos of civilian victims and chanted "Free Palestine," in what was the largest demonstration in Poland since Israel launched airstrikes on the Strip two weeks ago.

"We lived through the same thing in 1939, when a visionary got the appetite for more land," said protestor Antoni Brzeziucha. "They lived through the Holocaust themselves, and now they're doing the same thing: killing innocent woman and children."

Jerusalem  - A human rights groups accused Israel Saturday of apparently using white phosphorus in violation of international law.

Human Rights Watch (HRW) said Israel seemingly employed the substance as an obscuring tool, which is legal, but said that given Gaza's high population density, and the chance that civilians would be hurt, Israel should discontinue the use.

Gaza  - Five Palestinians from a single family were killed Saturday night when an Israeli airstrike targeted their house in the Jabalia section of the Gaza Strip, witnesses said.

According to medical sources, 36 Palestinians were killed Saturday, including the incident in which several members of the same family were killed.

Since December 27, when Israel launched its offensive in the Gaza Strip, at least 830 Palestinians have been killed and over 3,300 injured.

Tehran  - Iranian President Mahmoud Ahmadinejad said Saturday that the United Nations and its Security Council have lost credit over the crisis in Gaza Strip.

"After more than two weeks, the UN Security Council has finally issued a resolution, which is however vague from the beginning to the end," Ahmadinejad said at a religious ceremony in Tehran, referring to the latest UN resolution calling on an immediate ceasefire in the Gaza Strip.

Tens of thousands took part Saturday in worldwide protests against Israel's 15-day bombardment and infantry deployment into the Gaza Strip.

In Germany, more than 35,000 people took to the streets in demonstrations organized mainly by ethnic Turks, Palestinians and other predominantly Islamic minorities.

The biggest demonstration in Germany was in the western industrial city of Duisburg, where 10,000 demonstrators attended a rally organized by the Milli Gorus Islamic community, a Turkish Islamist group.