U.S. Secretary of State John Kerry is working for Israel and Hamas to agree to further halts in the Gaza bloodshed ahead of Egyptian-led peace talks, an official said Sunday.

Kerry returned to Washington early Sunday after a weeklong mission to the Middle East that failed to reach a permanent ceasefire to stop the 20-day conflict which has killed more than 1,000 people, mostly Palestinian civilians.

Prime Minister Tammam Salam on Sunday ruled out a role for Hizbullah in the ongoing conflict between Israel and Gaza-based Palestinian groups, urging an end to the Israeli “aggressiveness” and “hegemony” in the region.

“If we can put an end to Israeli hegemony and to Israeli aggressiveness in this region, we will put an end to many violence in this region and if we cannot do that, violence will prevail,” Salam said in English in an interview on CNN.

French police arrested 70 people at a banned pro-Palestinian protest in central Paris on Saturday that degenerated into clashes between demonstrators and armor-clad riot squads.

The rally had drawn 4,000 people to the capital's Place de la Republique, the interior ministry said, while organizers put the turnout at 10,000.

About 1,000 pro-Palestinian demonstrators marched through Berlin Friday, closely watched by police for any banned anti-Semitic slogans and separated from pro-Israel rallies.

More than 1,000 officers were on guard in the rainy capital for the rally against Israel's Gaza offensive that has killed more than 845 people, most of them Palestinian civilians.

French police have banned a protest against Israel's Gaza offensive that was due to take place in Paris on Saturday, following several similar rallies that turned violent.

The ban, announced by police on Friday, comes in the wake of clashes earlier this month at pro-Palestinian demonstrations in which some protesters shouted anti-Semitic slogans and fought with police. 

The European Union called Friday for an "immediate" investigation after 15 Palestinians were killed when an Israeli shell slammed into a U.N.-run shelter in Gaza.

"We are obviously extremely concerned about the continued escalation of the violence in Gaza ... and the deplorable increase in the number of civilian deaths," European Commission spokeswoman Maja Kocijancic said.

Israeli security forces were on heightened alert Friday after several Palestinians were shot dead during a huge protest in the West Bank against Israel's military offensive in Gaza.

Palestinian medical and security sources told Agence France-Presse that five Palestinians were killed in the West Bank on Friday in two separate incidents involving both Israeli troops and Israeli settlers.

Israeli security forces were on heightened alert Friday after a Palestinian man was shot dead during a huge protest in the West Bank against Israel's military offensive in Gaza.

Palestinian factions in the West Bank declared a "Day of Rage" after the Thursday night clashes, which took place around the West Bank and in some sectors of Israeli-annexed east Jerusalem.

As diplomatic efforts to end the Gaza bloodshed gain pace, Israel may have managed to weaken Hamas' firepower, but it is far from achieving a full demilitarization of the Palestinian enclave, experts say.

After 17 days of an unrelenting offensive against Hamas in Gaza, Israel is facing a race against time to complete their stated mission of destroying the tunnels which allow Hamas fighters to reach Israeli territory.

The Palestinian mission in France said on Thursday that it had received death threats in a letter posted from Israel and claiming to carry a virus.

"We received this letter this morning threatening to kill members of the Palestinian mission in France and those who took part in recent demonstrations for Palestine," Noha Rashmawi, the chief of staff at the mission, told Agence France Presse.