Earlier on Saturday, Israeli army opened fire at four Palestinian militants from the Islamic Hamas movement near the Gaza-Israel border east of Gaza City, killing three at the scene and badly wounded the fourth who were shifted to hospital later, according to medics at Shifa Hospital in Gaza City.

Meanwhile, Palestinian security sources report that Israeli army shot dead another Palestinian allegedly also from Hamas near the border between southern Gaza Strip and Israel.

Shortly after the two incidents, Hamas' armed wing Izz el-Deenal-Qassam Brigades claimed the four militants in a leaflet, saying they were shot when they were on a mission near the border.

Abu Obaida, a spokesman for al-Qassam Brigades, said in a written statement faxed to reporters that the three killed militants at border east of Gaza City were members of his group, adding they were "on a jihad mission when the army of occupation targeted them."

However, he did not explain what kind of mission the militants were carrying out near the border with Israel in eastern Gaza.

Abu Obaida stressed that the "crime of killing the three fighters proves that the occupation army was not interested in the state of calmness," despite its unspecified mission near the border with Israel.

However, an Israeli military spokeswoman said that Israeli army opened fire at the Palestinians as they were trying to plant the explosive device at the border fence between eastern Gaza and Israel.

But she denied the separate killing incident in southern Gaza border area, where a fourth Palestinian man was allegedly killed by Israeli army. "I was sure that Israeli army did not attack the Palestinian in southern Gaza," the spokeswoman said.

Last week, Hamas said that the half-year-old ceasefire had expired, owing to "the continuing Israeli crimes" in West Bank.

But Egyptian mediators announced later they have persuaded Israel and the militant groups for self-restraint.

Hamas, which leads the current Palestinian unity government, has not officially confirmed or denied the saying of the Egyptian security delegation.

However, a spokesman for Hamas named Fawzi Barhoom called on Palestinian militant groups to "study the mechanisms to respond to the Israeli army crimes," vowing that his movement will not take negative stance before the Israeli violations.

Nafez Azzam, a senior Islamic Jihad (Holy War) leader in Gaza, also told reporters on Saturday that the killing of the four Palestinians "is an indication that Israel doesn't understand the language of dialogue."

"I'm wondering how Arabs and Palestinians are eager to keep presenting initiatives to Israel, while Israel is not paying attention to such initiatives and keeps its aggression on the Palestinians," said Azzam.

(Xinhua News Agency April 29, 2007)