Violence between Israel and the Palestinians had on Saturday mounted in the Hamas-ruled Gaza Strip while a Palestine Liberation Organization (PLO) official said the Palestinians seek the U.S. guarantees to resume the stalled Middle East peace process.

Palestinian and Israeli security sources said on Saturday that Palestinian gunmen and Israeli soldiers traded fire near Gaza Strip-Israel borders east of the southern town of Khan Younis, wounding eight Palestinians, including two militants and six civilians.

Palestinian security sources told Xinhua that fierce armed clashes erupted east of Khan Younis between Palestinian fighters and an Israeli army force which was stationed at the borderline area, after Israeli troops fired several artillery shells at the area.

The armed wing of the Democratic Front for the Liberation of Palestine (DFLP) and al-Aqsa Martyrs Brigades, the armed wing of Palestinian President Mahmoud Abbas' Fatah party, said in a joint statement sent to reporters that their militants clashed with Israeli soldiers in the area.

"Our fighters targeted four Israeli army jeeps and clashed with the Israeli army force using automatic machine guns and R.B.J. missiles," said the statement, adding that the Israeli forces fired artillery shells and helicopters opened fire at them, wounding two.

An Israeli army spokesman told Xinhua on telephone that gunmen from al-Aqsa Brigades approached the fence of the borders between southeastern Gaza Strip and Israel and opened fire at the Israeli army force, adding "no one from the force was hurt."

"Calm dominated the area after helicopters hovered over the area," said Avihai Adra'ei, the Israeli army spokesman, adding " the Israeli army force responded to the fire and no soldier was hurt."

Meanwhile, Palestinian medics at Nasser Hospital in the town said four Palestinian civilians were moderately injured after Israeli helicopters opened fire at the Palestinian homes at the neighborhood of al-Faraheen east of Khan Younis.

Hammad al-Regeb, Hamas movement's spokesman in southern Gaza Strip, said in a press statement sent to reporters that his movement "will not keep silence after the Israeli occupation forces attack eastern Khan Younis," adding "the soldiers and the settlers won't be excluded from our attacks."

The security sources also said Israeli naval forces opened fire on Saturday at Palestinian fishing boats in the sea off Gaza Strip, adding no injuries or damages were reported.

Gaza fishermen have a limited 4-mile (6.4 km) zone for fishing, where Israeli naval forces chase them all the time.

In the West Bank, two Palestinians were moderately injured after Israeli soldiers opened fire at their car near an Israeli army checkpoint east of the southern Gaza Strip town of Hebron, said Palestinian sources, adding the two wounded are Palestinians working in Israel.

Meanwhile, a member of the PLO's leading body said Saturday peace talks between Israel and the Palestinians are difficult to resume without U.S. guarantees.

"It is early to talk about any resumption of the negotiations in the absence of warrants that could secure its success," Hannan Ashrawi, who comes from the PLO's executive committee, told Xinhua.

Washington, through its Middle East envoy George Mitchell, proposed that Israel and the Palestinian National Authority (PNA) start indirect talks on the borders of the future Palestinian state before going back to face-to-face talks which stopped in December 2008.

But Ashrawi said the U.S. administration "wants to restart the negotiations at no cost and this is unacceptable for the Palestinians."

Negotiations must be restricted by a ceiling of time and there must be guarantees to oblige Israel to carry out its obligations, Ashrawi said.

The PNA wants Israel to freeze Jewish settlement in the West Bank and East Jerusalem before restarting the peace process.

Ashrawi said the PNA asked for clarifications on the U.S. proposal for indirect talks "and this is still under discussions."

On Thursday, Abbas met an aide to Mitchell in Ramallah, local daily Al-Ayyam reported that Abbas told Mitchell's assistant, David Hale, that the Arab world would decide on the U.S. proposal when an Arab League committee meets in Cairo early next month.

Sources said the answers to the PNA's questions, carried by Hale, "were not clear enough to allow a decision to be made."