Video Credit: YouTube

GAZA CITY, Gaza Strip (AP) — The U.N. chief and the U.S. secretary of state headed to Cairo on Monday for the highest-level attempt yet to end two weeks of Israel-Hamas fighting that has killed at least 510 Palestinians and 20 Israelis and driven tens of thousands of Gaza residents from their homes.

Despite the new cease-fire efforts by U.N. Secretary-General Ban Ki-moon and U.S. Secretary of State John Kerry, Israeli aircraft continued to strike homes in Gaza while Hamas fired more rockets and tried to infiltrate into Israel.

In one Israeli strike, 25 people were buried under the rubble of a home in the southern town of Khan Younis, including 24 from the same family.

"Twenty-five people!" said family member Sabri Abu Jamea. "Doesn't this indicate that Israel is ruthless? Are we the liars? The evidence is here in the morgue refrigerators. The evidence is in the refrigerators."

Hamas militants, meanwhile, tried to sneak into Israel through two tunnels, the latest in a series of such attempts. The Israeli military said 10 infiltrators were killed after being detected and targeted by Israeli aircraft.

Hamas also fired 50 more rockets at Israel, including two at Tel Aviv, causing no injuries or damage. Since the start of the Israeli operation, Hamas has fired almost 2,000 rockets at Israel.

Despite the rising death toll, there was no sign of a let-up in the violence.

Israeli Defense Minister Moshe Yaalon said Monday he is prepared to continue the offensive "as long as necessary" to halt rocket fire and other attacks from Gaza on Israelis.

Israel accepted an Egyptian call for an unconditional cease-fire last week, but resumed its offensive after Hamas rejected the proposal.

Hamas says that before halting fire, it wants guarantees that Israel and Egypt will significantly ease a seven-year border blockade of Gaza.

"The resistance (Hamas) will not respond to any pressure," Hamas spokesman Sami Abu Zuhri said in a text message, in a reference to the renewed cease-fire efforts. Kerry is also pushing for an unconditional cease-fire.

Read more at Associated Press