The Palestinian militant group Hamas has announced an immediate ceasefire with Israel in Gaza.
A statement read by a Hamas spokesman said the group would hold fire for a week to give Israel time to withdraw its forces from the Gaza Strip.
The move came hours after a unilateral Israeli ceasefire came into effect.
Some Israeli troops have begun pulling out of the Gaza Strip. Prime Minister Ehud Olmert said Israel wanted to leave Gaza "as soon as possible".
Earlier, there was more rocket fire from Gaza into Israel.
... Our demand is the withdrawal of the enemy forces from the Gaza Strip within a week, along with the opening of all the crossings for the entry of humanitarian aid, food and other necessities for our people in the Gaza Strip
The BBC's Paul Wood entered northern Gaza via the Erez crossing as part of the first group of journalists to gain independent access to the Strip from Israel.
He says that in the town of Beit Lahiya he saw the first real destruction -streets churned up by Israeli heavy armour, overturned cars, a lake of raw sewage in the street and a mosque left as a charred ruin.
Hamas officials stopped the BBC from filming at one site where bodies were still being removed - a sign, perhaps, that there had been some kind of military target nearby, our correspondent says.
Hamas' deputy chief in Syria, Moussa Abou Marzouk, said the ceasefire was in the name of all "Palestinian resistance factions".
"We... announce a ceasefire of our factions in the Gaza Strip and we stress that our demand is the withdrawal of the enemy forces from the Gaza Strip within a week, along with the opening of all the crossings for the entry of humanitarian aid, food and other necessities for our people in the Gaza Strip."
Israelis and Palestinians give their views on Israel's ceasefire announcement
One rocket hit a house in Ashdod, injuring lightly two people, police said.
The stopping of rocket fire had been a chief aim of the military campaign.
Israeli troops killed a Palestinian near the southern Gazan town of Khan Younis on Sunday morning, reports from Gaza said. If confirmed, the death would be the first fatality since the ceasefire began.
At least 1,300 Palestinians, according to Palestinian sources, and 13 Israelis have been killed since Israel launched its offensive on 27 December.
Palestinian medics say at least 50 bodies have been pulled from the rubble since Israel halted its offensive.
The BBC's Christian Fraser, in Rafah on the Gaza-Egypt border, says many of the 40,000 people who fled the town during the conflict, were returning to pick through the ruins of their homes on Sunday.
People are salvaging whatever they can, our correspondent says - even the broken bricks and corrugated iron are taken away on donkeys.
Hamas is still very much control in the town, our correspondent adds. One fighter told the BBC their determination and ability to fight was undiminished.
Meanwhile, heads of state from across Europe travelled to Egypt for a summit with Egyptian President Hosni Mubarak, Palestinian Authority leader Mahmoud Abbas and UN chief Ban Ki-moon to try to shore up the ceasefire.
They discussed how to make the ceasefire durable and respected by Hamas, how to get aid to Gaza and beginning the process of rebuilding there.
Speaking after the talks, UN Secretary-General Ban Ki-moon said he would be sending a team to assess the immediate humanitarian needs of the people in Gaza.
"Within 10 days, I think we'll be able to make an assessment report and we will issue a humanitarian urgent, a humanitarian flash appeal."
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