BBC
Israel forces enter northern Gaza
Israeli tank at border with northern Gaza
Israeli tanks have reportedly crossed into northern Gaza
Israeli ground forces have reportedly entered northern Gaza, intensifying an assault on the territory sparked by the capture of a soldier by militants.
Palestinian witnesses said Israeli tanks had crossed the border into Gaza near the town of Beit Hanoun.
Earlier on Wednesday, Israeli troops entered southern Gaza and air strikes on the area continued all day.
On the West Bank, Israel has detained at least 10 ministers and lawmakers from the Hamas-led government.
Among those held after the raids in Jenin and Ramallah were four cabinet ministers, including Deputy Prime Minister, Nasser al-Shaher.
In Qalqiliya the Hamas mayor and his deputy were taken into custody.
The BBC's Gaza correspondent, Alan Johnston, says Israel is dramatically stepping up pressure on the Hamas government in order to secure its soldier's release.
Gaza Strip in detail
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Cpl Gilad Shalit was seized by Palestinian militants in an attack on an Israeli border post on Sunday, that also left two Israeli soldiers dead.
Israel has threatened a huge military response if Cpl Shalit is not released and has been massing its tanks along the border with Gaza.
Separately, Palestinian militants in the West Bank are reported to have killed an Israeli settler they said they had abducted at the weekend.
Palestinian security sources were quoted as saying the body of the 18-year-old man, Eliahu Asheri, had been recovered in the city of Ramallah.
Air strikes
Reports of the Israeli incursion into northern Gaza come a day after Israeli forces pushed through the south of the territory, taking up positions near the town of Rafah.
Palestinians evacuating their home close to Gaza's airport
We are living, but we feel as if we are dead
Doaa Abu-Harb
Student, Rafah
Voices from Gaza
In pictures: Gaza offensive
Threat to abducted settler
Air strikes continued throughout Wednesday, with missiles striking a road near the Khan Younis refugee camp and the premises of the Islamic University in Gaza City.
No casualties have been reported so far.
On Tuesday night, Israeli jets struck bridges and a power station in Gaza.
The overnight raid cut electricity to much of Gaza and nervous civilians in north of the territory stockpiled batteries and candles, as well as food and water.
Israeli military said some of the strikes were intended to impair militants' ability to move the soldier they are holding hostage.
Israeli Prime Minister Ehud Olmert said Israel would not hesitate to "carry out extreme action" to free the captured soldier but said Israel did not want to re-take control of Gaza.
UN warning
Palestinian Prime Minister Ismail Haniya, of the governing Hamas party, criticised Washington for giving approval to the Israeli incursion.
Mr Haniya said Washington had "given the green light to aggression" and called on the United Nations to step in to prevent an escalation in violence.
A spokesman for US President George W Bush has said Israel has a right to defend itself and the lives of its citizens.
CAPTURED ISRAELI SOLDIER
Undated family picture of captured Israeli soldier Gilad Shalit
Cpl Gilad Shalit, 19 years old
Lost an uncle in the 1973 Arab-Israeli war
First Israeli soldier kidnapped by Palestinians since 1994
Family waits for news
Press review
The spokesman said Hamas must shoulder the blame for the Israeli assault because militants linked to it had kidnapped Cpl Shalit.
Mr Haniya has urged the UN Security and the Arab League to move to end the crisis in Gaza.
"The Israeli occupation must put an end to its aggression before the situation gets complicated and the crisis gets worse," Mr Haniya said.
UN Secretary General Kofi Annan said he hoped for a swift diplomatic solution to the crisis in Gaza. He warned that the crisis risked inflaming tensions extending across the region.
Earlier on Wednesday, Israeli jets flew low over a house in Syria used by President Basher al-Assad.
Israel accuses Damascus sheltering Hamas leaders involved in Cpl Shalit's abduction.
BBC
bbc againIsrael has accused the Syrian-based leadership of Hamas of being behind the kidnapping of Israeli soldier Cpl Gilad Shalit.
The Hamas leader in exile is Khaled Meshaal, a hardliner within the militant group, who survived an Israeli assassination attempt on his life back in 1997.
Khaled Meshaal
For many Palestinians, Khaled Meshaal is a national hero
The Israelis frequently accuse Damascus and militant Palestinian groups based there of orchestrating violence against them.
For the Israelis and the Americans, Khaled Meshaal is an uncompromising enemy of peace and the state of Israel.
For many Palestinians, he is a national hero, just like the guerrillas who kidnapped the Israeli soldier.
It is difficult to know whether orders did in fact go out from Mr Meshaal's office in Damascus.
The Israelis have not made public any evidence they have of such involvement.
But Mr Meshaal's views are well-known, and he has always supported Palestinian attacks on Israelis.
Like many Palestinians, he believes that such attacks are a legitimate act of resisting the Israeli occupation.
Expelled by Jordan
Mr Meshaal gained international fame following an attempt by Israeli agents to poison him when he lived in Jordan back in 1997.
The Israelis accused him then of masterminding suicide attacks on Israeli civilians.
Two years later, Jordan bowed to American pressure and expelled him.
After a brief stay in the Gulf, he moved to Damascus.
When the spiritual leader of Hamas, Sheikh Ahmad Yassin, was killed by the Israelis in 2004, Mr Meshaal was chosen as the head of Hamas's political bureau.
National unity
The organisation's secretive structure means the extent of his authority over the Gaza hierarchy and the organisation's militant wing is not entirely clear.
But there seems to be an emerging consensus among Palestinian factions that attacks on Israelis are justifiable as long as that they do not target Israeli civilians inside Israel.
The recent document of national unity adopted by the two main factions, Fatah and Hamas, endorses attacks on Israelis as long as they take place within the territories occupied by Israel since 1967.
That is the land the Palestinians want to have as a future state.
Hamas has, of course, still not renounced its aim of creating a state on all the territories of historic Palestine prior to the creation of Israel, which in effect means destroying the Jewish state.
I invite our other members to add information as it becomes available. Please avoid posting rumors at this time, thank you.Militants 'kill' Israeli settler
Popular Resistance Committee members with "Eliyahu Asheri's ID"
Militants show what they say is proof of Eliyahu Asheri's identity
A Palestinian militant group has reportedly killed a young Jewish settler who it says was seized on the West Bank.
The body of Eliyahu Asheri, 18, who lived in Itamar settlement, was found near Ramallah.
The Popular Resistance Committees had earlier showed a photocopy of his ID.
Israel had not confirmed that he had been kidnapped, saying only that he was missing and the authorities were concerned for his safety.
The reports come as Israel continues its operations in Gaza, sparked by seizure of an Israeli soldier by militants on Sunday.
Mother's plea
At the Gaza City conference on Wednesday, the ID photocopy was held up by Popular Resistance Committees spokesman Abu Abir.
Miriam Asheri
Miriam Asheri had appealed for her son's release
"We will kill the settler unless the aggression against the Gaza Strip stops," he warned.
Eliyahu Asheri's parents reported him missing when he failed to return home on Monday.
His mother, Miriam, said: "We turn to those who are holding Eliyahu and really, really request that they take care of him.
"We really hope that they will return him alive."
Israel has vowed to take "extreme action" if the soldier captured in Gaza, Cpl Gilad Shalit, is not released.