Two separate predawn Israeli airstrikes on the southern Gaza Strip have killed four Palestinian militants, the Hamas movement and the Israeli military said Thursday morning.

In a statement to the media, the Islamist movement named two of the fatalities as 25-year-old Shaher Abdel Karim and 22-year-old Imad Abu T'ima, and said they were on guard duty when they were struck by an Israeli missile east of Khan Younis.

In a second statement, the Hamas military wing, the Izz el-Deen al-Qassam Brigades, said Abdullah al-Asstal and Hani Abu Rumila were killed in aerial attack as they were preparing an ambush east of the city.

An Israeli military spokeswoman in Tel Aviv confirmed the strikes and said the second was carried out against militants who were placing an explosive device against the Gaza-Israel border fence, for use against Israeli troops.

Some 80 devices had been placed this year, she said.

Elsewhere, in a statement to mark 60 years since the United Nations voted to partition Palestine into separate Jewish and Arab states, Hamas said Israel needs to be wiped out by "armed resistance".

"We are determined, with the help of Allah to uproot this cancer (Israel) by armed resistance, no matter what the cost in blood and sacrifices," the statement said.

"What has been taken by force should be regained by force," the statement added.

UN General Assembly resolution 181, passed on November 29, 1947, with 33 in favour, 13 opposed and 10 abstentions, was rejected at the time by Arab states and the local Palestinian leadership.

Hamas said Thursday it rejected the UN vote and stated that "Palestine is one unified geographical unit, and can never be partitioned or sliced by resolutions or agreements."

"There is no compromise on the Arab and Islamic characteristics of Palestine," the Islamist movement, which wants an Islamic state in all of historic Palestine, said.

"The resolution legalized the partition of the lands of Palestine between its legal residents, who were expelled out of it by force, and the illegal newcomers of Jews and Zionists," the leaflet claimed.

The Hamas statement came two days after Israel and the Palestinian Authority agreed at a conference in Annapolis, Maryland, to try and negotiate a peace deal within one year, which would see a Palestinian state established in the West Bank and Gaza Strip, territories the Jewish state captured from Jordan and Egypt respectively, in the 1967 war.

"This anniversary of partition coincided with [the] Annapolis conference. The US wanted through this conference to eliminate the Palestinian cause in order to complete the chapters of conspiracy," the Hamas statement said.

The movement said it held the UN responsible "for issuing the unfair resolution 181 which divided Palestine, and for the suffering and pain our people had passed over the past 60 years."