( dpa ) - Israeli troops rolled into northern Gaza Tuesday, sparking fierce gunbattles with local militants and killing at least 16 Palestinians in the deadliest Israeli military incursion since Hamas took control of the Strip seven months ago.
Another 45 people were injured, a number of them seriously, Gaza City's Shiffa hospital said.
Meanwhile, a Palestinian sniper from Gaza also killed a foreign volunteer in an Israeli kibbutz (agricultural commune) bordering the Strip, a spokesman for the kibbutz, Ain Ha'Shlosah, told Deutsche Presse-Agentur dpa.
The 20-year-old volunteer from Ecuador was shot in the back while working in a potato field near the Israel-Gaza border fence.
One of the Palestinian dead was the son of Mahmoud al-Zahar, a senior Hamas hardliner.
Al-Zahar, a co-founder of Hamas, served as foreign minister from March 2006 to March 2007 in the Hamas-led Palestinian government formed shortly after the radical Islamic movement beat the secular Fatah party of President Mahmoud Abbas in January 2006 legislative elections.
His son Hussam, 23, was taking part in Tuesday's fighting when killed, residents said.
Hussam is Mahmoud al-Zahar's second son to die in Israeli- Palestinian violence. Another son, Khaled, was killed in a September 10, 2003 Israeli airstrike on his house. Al-Zahar and his now paralyzed wife were both moderately injured in that airstrike, which had come a day after double suicide bombings in Jerusalem and south of Tel Aviv.
"This crime is the fruit of US President George Bush's visit to the region," al-Zahar told reporters at the morgue after identifying his son's body.
Hamas will "respond to this crime in the suitable time and way," he threatened. Referring to his son's death, he said, "there is no difference between martyrs. All of them fall for the sake of the land."
Abbas too condemned the Israeli incursion. "The Palestinian people cannot remain silent to such massacres and slaughter," he told reporters in Ramallah. Such activities "do not serve the peace that we seek," he added.
Witnesses said a number of tanks and bulldozers drove some 400- 500 metres into northern Gaza around dawn, reaching up to the eastern outskirts of Gaza City. They began levelling makeshift structures and agricultural fields, from which militants have been firing rockets into Israel.
Hospital officials said nearly all the dead were militants, most of them members of Hamas' armed wing. A 67-year-old civilian bystander was also among the dead, however.
A spokeswoman in Tel Aviv said the Israeli military fired from the air and the ground at Palestinian militants who confronted the troops with mortars and semi-automatic fire.
Violence in Gaza has been steadily escalating since Hamas seized sole control of the Strip from security forces loyal to Abbas and Fatah last June.
Since then, militants have been stepping up their rocket and mortar attacks from Gaza at southern Israel, with Hamas taking responsibility for many of the mortar strikes, and other militant groups, notably the Islamic Jihad, taking the forefront in the rocket strikes.
Israel has responded with brief military incursions as well as targeted airstrikes.
The latest escalation in fighting came after Abbas' and Israeli Prime Minister Ehud Olmert's negotiators met in Jerusalem Monday and for the first time in seven years began serious peace negotiations.
The negotiations were due to have started immediately after a November 27 peace conference, in Annapolis, Maryland, but were held up amid a dispute over Israel construction in Jerusalem areas it wants to keep for itself as part of a future peace deal.
But after last week's visit by US President George W. Bush, the sides announced the start of the talks on the "core issues" of their mutual conflict, including on the status of Jerusalem, the borders of the future Palestinian state and the Palestinian refugee problem, despite their ongoing argument.