Hamas negotiator Moussa Abu Marzouk in Cairo. Israel has been accused of not taking the talks seriously. Photograph: Asmaa Waguih/Reuters
Attempts at talks between Palestinians and Israelis aimed at ending theGaza conflict look in danger of breaking down following warnings from both sides.
Hamas's lead negotiator said the Palestinians may abandon the Cairo-based negotiations if Israel does not take them more seriously, and says that the Islamist group may continue its war of attrition if its demands are not met.
Israel said it would not return to the talks as long as Palestinian militants in Gaza kept up cross-border rocket and mortar fire.
In an interview with the Guardian Hamas's deputy chairman, Moussa Abu Marzouk, said the Palestinian delegation would decide on Sunday whether or not to leave Cairo – where they have negotiated indirectly with their Israeli counterparts for a week.
"There will be a meeting in order to decide if we are going to continue the talks or not – because there is no seriousness from the Israeli side about the talks," Marzouk said late on Saturday night, in the hotel where negotiations have centred.
Israel's prime minister, Binyamin Netanyahu, said on Sunday: "Israel will not negotiate under fire. At no stage did we declare [Israel's military offensive] was over.
"The operation will continue until its objective – the restoration of quiet over a protracted period – is achieved. I said at the beginning and throughout the operation – it will take time, and stamina is required." Israeli air strikes and shelling killed three Palestinians in Gaza on Sunday, including a boy of 14 and a woman, medics said, in a third day of renewed fighting that has jeopardised international efforts to end the conflict.
Hamas has complained that throughout negotiations – conducted via Egyptian intermediaries – the Israelis had never formally responded to any Palestinian demands, which centre on ending an eight-year blockade of the Gaza strip. Marzouk also claimed that the Israeli delegation had made no attempt to negotiate since the end of a temporary ceasefire on Friday morning, when the Israeli team flew back to Jerusalem to observe the Jewish sabbath, and did not return.
"They don't talk about peace or ceasefire during their religious ceremonies," said Marzouk. "But they can kill and destroy as they did in Gaza on Saturday. It's open season for killing."
Marzouk said Hamas had not made a final decision about escalating its own attacks on Israel, should the talks fail – but claimed that "all the options are available to the Palestinian people in order to them to gain their rights". He said: "If we don't have justice and rights, we will keep resisting our enemies until we get them … If they don't give us our rights today, we will continue the battle."
Marzouk said the concession Hamas most wanted from Israel was the right to build a port and airport in Gaza, facilities promised to the Palestinians under the Oslo peace deal. In return, he said Hamas had no problem with relinquishing power to a Palestinian Authority-led unity government that "should control everything in Gaza", including its border crossings.
But he said Hamas would not agree to disarm while the Gaza strip was still occupied. "Disarming is out of the question. There is no discussion. It's not on the negotiation table. There is no force that can take away from the Palestinian resistance their right to resistance, nor their tools to resist."
Marzouk also denied that Hamas should down its arms in order to protect innocent lives in Gaza, saying that it was Israel's responsibility to stop bombing civilians. He also denied that Hamas fighters endanger civilians by firing rockets from civilian areas.
"I cannot understand how [Hamas's critics] always blame the weak, the party that gets attacked. Who started the battle? … Did Israel really have to kill all this number in order to get their targets? To demolish all these houses in order to achieve their goals? The ones who should be blamed are the Israelis."
Marzouk said it was hard for Hamas fighters to avoid civilian areas in such a densely populated tract of land as Gaza, and argued that Israel had the sophisticated military equipment necessary to avoid killing any civilians. "Why do they keep killing all these civilians even though they have these [accurate] weapons? They don't miss the target even by a few centimetres … The fact is unquestionable. They kill for the sake of killing."