Israeli President Shimon Peres has warned of the demographic consequences on the Jewish state of ongoing settlement in the occupied West Bank.

"Israeli settlements in densely populated Arab areas could bring about a demographic change about which we would do well to think hard about before acting," he said in remarks broadcast on both army radio and Israel public radio.

European Commission chief Jose Manuel Barroso called on Sunday for a return to Israeli-Palestinian talks, warning the peace process must not become "an orphan of the Arab Spring."

Barroso was speaking after talks with Palestinian Prime Minister Salam Fayyad on the first day of a trip which includes stops in the West Bank and Israel.

An explosion injured five Palestinian children in the central Gaza Strip on Saturday, a hospital said, blaming Israeli tank fire.

The children -- aged four to 10 and from the same family -- were in light to moderate condition after being hit by a shell fired by an Israeli tank east of Deir al-Balah, according to the al-Quds hospital in the town.

The armed wing of the Hamas movement which rules Gaza threatened Saturday to end a three-day-old Egyptian-brokered truce with Israel following a flurry of air strikes.

"The air raids by the Zionist enemy are new crimes. We will not stay silent in the face of the crimes," a statement from the Ezzedine al-Qassam Brigades said.

Three Palestinians were killed and an Israeli wounded in air raids and rocket fire Saturday, medics said, as the armed wing of Hamas threatened to call off an Egypt-brokered truce.

"The air raids by the Zionist enemy are new crimes. We will not stay silent in the face of the crimes," said Ezzedine al-Qassam Brigades of the Islamist movement Hamas which rules the Gaza Strip.

Palestinians said Thursday they had recovered the bodies of two militants from a tunnel damaged by an Israeli air strike on Gaza, raising to 10 the death toll in the territory since Monday.

Thaer Mohammed al-Bik, 30, and Mohammed Zuhair al-Khaldi, 26, were killed by gas fumes as they carried out an inspection of the tunnel hit by Israeli fire on Tuesday, the military wing of Gaza's ruling Hamas movement said.

Palestinian militants fired rockets from Gaza into Israel for a fourth consecutive day on Thursday, the army said, despite an announcement by Hamas it had agreed to a truce with the Jewish state.

Seven rockets slammed into southern Israel after midnight, causing no casualties and another one was intercepted by the Iron Dome anti-rocket defense system, a military spokesman said.

An Israeli air strike on southern Gaza on Wednesday killed a "global jihad" militant who put together a deadly ambush on Israel's border with Egypt, the military said.

The strike targeted a man riding a motorcycle in the southern city of Rafah which lies on the border with Egypt, killing 21-year-old Ghaleb Ermilat, Palestinian medics said. Another person was wounded in the strike.

There was no let-up in rocket fire from Gaza on Wednesday, with at least 10 hitting the Jewish state despite seven Israeli air strikes overnight, police and the military said.

As the violence in and around Gaza entered its third day, Israeli police raised their level of alert in the towns and villages within rocket range, although there were no casualties in the latest strikes.

An Israeli air strike killed two Palestinian teenagers near the central Gaza Strip town of Deir el-Balah early on Tuesday, a Palestinian medical official said.

"Two citizens were killed in an Israeli air strike," the official said. "The bodies were only recovered this morning when an ambulance could get to the scene."