GAZA CITY, June 27: Eleven Palestinians were killed on Wednesday as Israel launched twin offensives in the Gaza Strip, triggering the deadliest violence since Hamas fighters overran the territory 12 days ago.

Israeli tanks and bulldozers rolled into Gaza City and the southern town of Khan Yunis in incursions launched overnight that swiftly sparked clashes with Palestinian fighters armed with guns and rocket-propelled grenades.

An air strike was called in near the Karni crossing between Gaza and Israel after gunmen were spotted approaching Israeli forces.

The army said the activity was against “terror threats” in Gaza, where Hamas fighters overran security forces loyal to Western-backed Palestinian president Abbas on June 15, effectively creating an Islamic enclave on Israel's doorstep.

Medics said 11 Palestinians were killed, including eight fighters in the armed Islamic Jihad, Hamas and the Al-Aqsa Martyrs Brigades linked to Abbas's Fatah party. Three civilians were killed, including a 12-year-old boy.

An Apache helicopter gunship swooped to the sound of heavy shooting and periodic explosions in eastern Gaza City while Israeli soldiers patrolled rooftops and Palestinian fighters ran through the streets, witnesses said.

At least 40 Palestinians and two Israeli soldiers were injured.

“We have a number of gunmen who were identified by our forces there (in Shujaiya area) and fired at in different incidents,” an army spokesman said before the operation in eastern Gaza City ended and Israeli soldiers withdrew.

In the south, two fighters from the Al-Quds Brigades and Hamas's armed Ezzedine al-Qassam Brigades were killed in clashes with Israelis in Khan Yunis.

“In the southern Gaza Strip, Palestinians fired anti-tank missiles and opened fire at the IDF forces there which are operating against terror threats.

During exchange of fire, the force identified hitting two,” the army said.

The violence came as envoys pressed a diplomatic agenda after Abbas met Israeli Prime Minister Ehud Olmert face-to-face at a summit in Egypt on Monday for the first time since the Hamas seizure of Gaza.

While the international community is seeking to further isolate Hamas — regarded as a terror group by Israel and the West — Arab leaders are pushing for reconciliation between the Islamists and their secular rivals in Abbas's Fatah party.

Abbas condemned the Gaza operations as a “criminal action” at a news conference with visiting Russian Foreign Minister Sergei Lavrov in the West Bank capital of Ramallah.

Hamas lashed out at the “barbaric massacre” and the “first bloody fruit of Sharm el-Sheikh” while Egypt warned that the offensives further aggravated an already extremely complex situation.

In Amman, the leaders of Jordan and Saudi Arabia — which brokered a since collapsed unity government — said they would back efforts to restore unity.

Egyptian President Hosni Mubarak's spokesman said on Tuesday that Riyadh and Cairo were ready to resume mediation between the factions.

On Monday, Olmert told the four-way summit with Egypt and Jordan he was prepared to free 250 prisoners from Abbas's Fatah party and that Israel would pass on tax money collected on behalf of the Palestinians.

Israel froze such transfers — mounting to several hundred million dollars — for 15 months while Hamas-led governments were in power, but agreed in principle to lift the embargo after Abbas set up a new emergency cabinet.—AFP