A six-month truce which aims to bring an end to a year of fighting that has killed seven Israelis and more than 400 Palestinians took hold in the Gaza Strip this morning.
However, both Israel and Hamas have voiced doubt over how long the Egyptian-brokered truce might hold.
Just before the truce went into effect an Israeli missile strike killed one Palestinian and wounded another near the border fence with Israel in the central part of the Gaza Strip, medical workers and militants said.
The truce began after another day of cross-border violence. Dozens of short-range Palestinian rockets and mortar bombs hit south Israel, without causing serious damage. Israeli air strikes hurt several Gazan gunmen.
"What they are calling a 'calm' is fragile and likely to be short-lived," Israeli prime minister Ehud Olmert said in a speech near Tel Aviv, using a loose term both the Jewish state and Islamist Hamas prefer in the absence of a formal pact.
"Hamas and other terrorist groups ... have not changed their stripes or turned into lovers of peace," he said yesterday, reiterating a threat to invade Gaza should the truce collapse.
Mr Olmert's office announced after the ceasefire began that he plans to visit Egypt next Tuesday for talks with President Hosni Mubarak on regional and bilateral issues.
For Hamas, which routed the forces of Western-backed Palestinian President Mahmoud Abbas to take over Gaza a year ago, suspending hostilities should spell some relief from an Israeli-led blockade on the impoverished coastal territory.
But Hamas's Izz El-Deen al-Qassam Brigade, the group's armed wing, said in a statement issued as the truce went into effect that the ceasefire was "not in anyway a free gift," to Israel and warned against any violations by the Jewish state.
Though Hamas refuses to recognise Israel, their indirect dealings via Cairo could also help the faction gain legitimacy in the West and reconciliation with Mr Abbas, who is in the midst of US-sponsored peace negotiations with Mr Olmert.
Western officials said Israel planned to allow in a slightly higher number of truckloads of goods starting on Sunday, provided the truce was still in place. The Palestinians have demand the full flow of imports restored.
Hamas rules Gaza but smaller Palestinian armed groups have in the past defied its ceasefire calls. The most recent Gaza truce, in November 2006, broke down quickly.
Hamas leader Ismail Haniyeh voiced confidence all factions would respect today's deal out of a sense of "national responsibility."
On an unusually conciliatory note, Mr Haniyeh told reporters the truce could offer "comfort" to Israelis who have suffered shelling from Gaza. But Hamas made clear it would not stop training and arms its fighters and was ready to resume attacks.
"We have no illusions that the Occupation (Israel) has good intentions toward our people, and should the Occupation foil the calm, it would mean a return to an even stronger resistance," said Abu Ubaida, spokesman for the faction's armed wing.
The truce does not cover the occupied West Bank, where Mr Abbas holds sway and where Israeli troops regularly operate. Bloodshed there could potentially trigger reprisals from Gaza.
Another variable is ongoing talks, mediated by Cairo, on the return of an Israeli soldier held in Gaza for almost two years.
Israeli officials said the reopening of the Rafah border crossing between Gaza and Egypt depended on a deal to free Sergeant Gilad Shalit.
Another Hamas leader, Khaled Meshaal, said Sgt Shalit's release depended on Israel freeing Palestinian prisoners, though the Olmert government has balked at many of the names on the list.
Israeli defence minister Ehud Barak, in an interview with the French newspaper Le Monde, said he could not predict whether the truce would last "two days or two months".
"Historically, we are on a collision course with Hamas. But it still makes sense to grasp this opportunity," he said.