A series of worldwide protests and continued calls from international leaders for a ceasefire were not enough to stop the ongoing conflict in Gaza, as Israel continued its week-long assault on Hamas targets throughout Friday.

One of the buildings destroyed in the latest airstrikes was a mosque that Israel claimed was being used to store weapons.

Some 20 houses were also targeted in Gaza on Friday, though Israel says it phoned ahead to warn those inside. The homes of more than a dozen Hamas leaders were reportedly destroyed in the raids.

Israeli planes also dropped leaflets for people to call in the locations of rocket squads, though it appeared that few people took up the initiative.

Nizar Kaddah, a Palestinian-Canadian who moved with his family to Gaza for a job, told Â鶹´«Ã½net that the bombings have made life "very difficult and miserable" for the people on the ground.

"I can hear from my home bombs everywhere, you know, especially at night," he said in a phone interview from his Gaza City home.

"They usually start bombing after, like, midnight until the early hours in the morning. It is very difficult and miserable in here."

Kaddah also said it has been hard for his family to get access to food and basic supplies.

Humanitarian issues

The United Nations said that a humanitarian crisis is developing as the conflict continues.

UN humanitarian coordinator Maxwell Gaylard said 2,000 people have been wounded so far and that there is "a critical emergency right now in the Gaza Strip."

Israel has said it is doing what it can to limit civilian casualties and that it has increased shipments of supplies to Gaza.

On Friday, Israel also allowed about 300 Palestinians with foreign passports to leave Gaza.

One Hamas leader said the Israeli-led attacks would not go unpunished.

"The Palestinian resistance will not forget and will not forgive," said Hamas legislator Mushir Masri. "The resistance's response will be very painful."

Thirty rockets, many heavier than those used in previous days, were launched from inside Gaza at Israeli targets on Friday.

Hamas also said it would retaliate against the death of Nizar Rayan -- a senior Hamas leader who was killed by a one-ton bomb that also killed 18 others, including 13 members of Rayan's family on Thursday.

There were also indications Friday that Israel could soon expand its military operation with a ground incursion into Gaza.

An estimated 400 people have been killed in Gaza during the week-long conflict. Three Israeli civilians and one soldier have also been reported dead.

Tens of thousands stage worldwide demonstrations

Tens of thousands of people held anti-conflict protests across the globe on Friday, calling for their local governments to bring sanctions against Israel and for the fighting to come to an end.

In London, several celebrities -- including former Eurythmics singer Annie Lennox and Bianca Jagger -- voiced their opposition to the conflict and called for Israel to halt its assault on Gaza.

A large protest in Bern, Switzerland, saw hundreds of marchers calling for both a ceasefire and sanctions to be brought against Israel.

Thirty-seven people were detained in Moscow after protesting the conflict outside the city's Israeli Embassy.

About 6,000 people chanted "Death to Israel" and "Death to America" in Tehran, Iran.

Iran's foreign minister, Manouchhehr Mottaki, said that if Israel launches a ground raid on Gaza it will be "the biggest mistake of the Zionist regime."

Egyptian officials sent hundreds of riot police to a Cairo mosque to keep protesters away and police arrested 40 members of the Muslim Brotherhood opposition group. Another 3,000 pro-Gaza supporters marched in the northern Sinai city of el-Arish.

Some 30,000 Jordanians made their support for Gaza known at a stadium in Amman, and 10,000-plus Muslims marched through Jakarta, Indonesia aiming fake missiles at the city's U.S. Embassy that were labeled "Target: Tel Aviv, Israel."

Similar anti-Israel protests took place in the capital cities of Afghanistan and the Philippines, as well as in several Turkish cities and in Damascus, Syria.

Syrian President Bashar Assad reportedly spoke with UN Secretary-General Ban Ki-moon on Friday and asked for the UN Security Council to adopt a resolution to force Israel to immediate stop its military actions in Gaza.

In Nairobi, Kenya, hundreds of Muslims held a rally at a central mosque. Many chanted for their government to cut off its ties with Israel.

In Sudan, thousands of protesters marched through Khartoum making anti-Israeli and anti-U.S. statements.

Continued calls for a ceasefire

On Friday, Israeli leaders also remained cool to calls for a ceasefire.

French president Nicolas Sarkozy is expected to push for a cessation of fighting when he visits the region next week. Meanwhile, U.S. Secretary of State Condoleezza Rice says she has no plans to make a similar trip.

"Hamas has held the people of Gaza hostage ever since their illegal coup against the forces of President Mahmoud Abbas," she said.

She said the United States wants to see a "durable and sustainable" ceasefire.

Democratically-elected Hamas seized control of Gaza from Abbas' Fatah forces in 2007. Abbas then set up a rival government in the West Bank.

Meanwhile, here in Canada, Liberal foreign affairs critic Bryon Wilfert called on all sides of the dispute to halt the violence so that desperately needed aid can reach the residents of Gaza.

"Canada wants to have a situation where both sides end the hostilities. A permanent ceasefire needs to be put in place," Wilfert told Â鶹´«Ã½net on Friday.

Foreign Affairs Minister Lawrence Cannon has previously urged for the two sides to work towards a ceasefire and for "Israeli and Palestinian leaders to remain committed to finding a comprehensive peace settlement."

Christopher Gunness, a United Nations Relief Works Agency spokesperson, said some aid has made it through in the last day. But he added that with each bomb that Israel drops, the situation worsens for children and families.

"Today, we got 63 trucks into Gaza ... as each bomb drops in Gaza so does the humanitarian crisis increase," Gunness said.

"We are struggling. We are working amidst the most awful, volatile security situation."

He said that so far aid organizations have only been able to get some fuel and food into bombed territory. He also noted that the medical situation is so desperate in Gaza that people with limbs blown off are being turned away because of a lack of supplies.

"If your foot is shot off -- and it's not life-threatening -- you'll be sent home," he said.

With files from The Associated Press and a report from CTV's Middle East Bureau Chief Janis Mackey Frayer