The leader of the military wing of Hamas has said there will be no truce in Gaza unless Israel lifts its siege, in comments broadcast hours after an attempt at a 24-hour ceasefire stalled with disagreements.
In an audio statement on Tuesday, Qassam Brigades commander Mohammed Deif said the ceasefire "will not take place unless the siege is lifted and the border crossings are all open".
Deif said the "balance of power" had changed during Israel's three-week invasion of Gaza, which began with air raids before Israel sent in ground forces, first to stop Hamas rocket fire and then to destroy tunnels dug by fighters.
"What the air force and your artillery shelling has failed to accomplish, will not be accomplished by ground forces," said Deif. "You are sending your soldiers to a definite slaughterhouse, God willing."
"The Zionist entity will not know security unless the Palestinian people live in peace."
Shortly after the statement was aired, the Qassam Brigades released a video that appeared to show a group of fighters emerging from a tunnel into Israel. In the footage, which was shown on the Hamas TV channel Al Aqsa, the men dash through what looks like a rural area, before attacking a watch tower.
Al Jazeera has not independently verified the authenticity of the video.
Israel continues to shell the Gaza Strip. At least 100 Palestinians were killed on Tuesday, according to Gaza officials. The total Palestinian death toll in more than three weeks of Israel-Hamas fighting has exceeded 1,200.
On the Israeli side, 56 people have been killed. That figure includes two Israeli citizens and a Thai worker killed by rockets fired into Israel by Gaza fighters.
Rockets in school
In a separate development, the UN agency that looks after Palestinian refugees said on Tuesday it had found a cache of rockets at one of its schools in the Gaza Strip and deplored those who had put them there.
Chris Gunness, spokesman for the United Nations Relief and Works Agency (UNRWA), condemned those responsible for placing civilians in harm's way by storing the rockets at the school but he did not specifically blame any particular party.
"We condemn the group or groups who endangered civilians by placing these munitions in our school. This is yet another flagrant violation of the neutrality of our premises. We call on all the warring parties to respect the inviolability of UN property," Gunness said in a statement.
Israel has targeted a few UNRWA sites during fighting in the current 22-day-old campaign, and has in the past said the agency's property was used for hostile purposes.