Israeli troops killed 11 Palestinian fighters in fierce clashes while ground troops backed by air power pushed into the Gaza Strip, stepping up pressure on the Hamas-run enclave.

Israeli troops and tanks rolled across the border into the central Gaza Strip to the outskirts of the Mughazi refugee camp, where they got locked in heavy firefights with Palestinian militants, medical sources and the army said.

The military called in two air strikes during the fighting that raged all day, killing five members of Hamas's armed wing, medics and witnesses said.

Another member of Hamas's Ezzedine al-Qassam Brigades was killed in fighting in the same area.

Around 26 Palestinians were wounded, including five seriously, in the intense clashes about one kilometre into Gaza, from which Israel withdrew all troops and settlers in 2005 after 38 years of occupation.

Several hours later a member of Hamas's smaller rival, Islamic Jihad, was killed by an Israeli rocket that witnesses and medics said was fired at a group of people seeking to rescue a wounded person.

An eighth fighter died in fighting in the same area, but his identity was not immediately known, while another three were killed in centre of the Gaza Strip on the evening.

Cameraman shot

Meanwhile, a cameraman working under fire for Hamas's Al-Aqsa television had both legs amputated. Imad Ghanem, 23, was first hit by a shell and then by two bullets fired into his crumpled body as it lay on the ground, medics said.

The military said the troops and tanks were "operating against terror infrastructure" in the central Gaza Strip and that it was investigating the circumstances of the incident in which the cameraman was shot.

"We identified hitting approximately 10 armed gunmen in two air strikes and exchanges of fire on the ground. Two soldiers were wounded by an RPG (rocket-propelled grenade) fired at a bulldozer in the central Gaza Strip and were evacuated," an army spokesman said.

An Israeli military source said that Hamas television cameramen "cannot be considered as journalists, as they are part of Hamas's armed wing and their films are used for propaganda and intelligence purposes."

Mr Ghanem was not wearing press-marked insignia but was carrying a video camera as he tried to film Palestinians evacuating a dead fighter during combat.

Israeli troops were also operating in northern Gaza on the outskirts of Beit Hanun, where two militants were wounded overnight. The army said the two were attempting to fire rockets at Israel.

Although Israel has vowed to bolster Palestinian president Mahmoud Abbas and his new Western-backed emergency government based in the occupied West Bank, it has sworn to continue attacks on militants.

Meanwhile the United States has welcomed the release of BBC reporter Alan Johnston in Gaza but said Hamas's role in winning his freedom would not change US policy towards the militant movement.

"Everybody is pleased that Mr Johnston is back safe and sound, reunited with his family," said State Department spokesman Sean McCormack.

"But I don't think that the world views Hamas any differently as a result of this," he added, rejecting the idea that the release should open a dialogue with Hamas, which the United States has labeled a terrorist group.

"We do not hold that view," Mr McCormack said.

-AFP