Israel withdrew the last of its troops from the Gaza Strip before dawn Wednesday, the military said, and pursued diplomatic efforts to stanch the flow of arms into the Hamas-ruled territory.
The timing of the pullout reflected Israeli hopes to defuse the crisis in Gaza before President Barack Obama entered the White House. The military said troops remain massed on the Israeli side of the border, prepared to take action in the event of renewed militant fire. Israeli navy ships shot rounds of machine-gun fire at the beaches of northern Gaza.
The military had no immediate comment on the gunboat fire.
Israel sent thousands of ground troops into the Palestinian territory earlier this month as part of a bruising offensive meant to permanently halt years of militant rocket fire on growing numbers of Israelis and to halt the smuggling of arms into Gaza.
Some 1,300 Palestinians were killed, more than half of them civilians, Gaza health officials and the United Nations have reported, a death toll that has provoked international outrage. In Israel, however, the war was popular because it was seen as a legitimate response to militants who now have one-eighth of the population within rocket range.
Both sides declared cease-fires that went into effect Sunday, though they remain shaky. Israel reported mortar shelling from Gaza on Tuesday, and the Palestinians say Israeli troops shot and killed two Gaza farmers along the border since the truce took hold.
The fighting ended before Israel achieved its aims, though world leaders have pledged to assist in efforts to keep militants from restocking war-depleted arsenals.
U.N. Secretary-General Ban Ki-moon left the region early Wednesday after touring Gaza and southern Israel. Ban called for an investigation into the Israeli shelling of U.N. compounds in Gaza during the fighting, which he termed "outrageous." He also called militant rocket attacks against Israel "appalling and unacceptable."
The Israeli army also confirmed it had launched an internal investigation into allegations about its during the Gaza Strip offensive.
White phosphorus is an incendiary agent used to illuminate targets or create smoke screens. International law does not prohibit its use in battle, but it can inflict serious burn wounds.
U.N. officials and in the 22-day Gaza campaign against the territory's Hamas rulers. Amnesty International has called Israel's firing of white phosphorus shells in densely populated residential areas of Gaza a war crime.
Israel has not publicly acknowledged using white phosphorus. But in response to the claims, the military said in a statement Wednesday that an "investigative team has been established ... to look into this issue."
Meanwhile, Israeli Foreign Minister Tzipi Livni was heading to Brussels on Wednesday, hoping to clinch a deal committing the European Union to contribute forces, ships and technology to anti-smuggling operations, officials said.
Last week, the United States signed an anti-smuggling deal with Israel calling for expanded intelligence cooperation between the two countries and other U.S. allies in the Middle East and Europe.
The United States promised to supply detection and surveillance equipment, as well as logistical help and training to Israel, Egypt and other nations in the region. The equipment and training would be used to monitor Gaza's land and sea borders.
The document also calls for the United States to expand work with its NATO partners, particularly in the Red Sea, Mediterranean Sea, Gulf of Aden, Indian Ocean and eastern Africa.
At the signing ceremony in Washington, Livni described the deal as "a vital complement for a cessation of hostility" in the troubled region. Shortly after, she said she hoped European countries, notably Britain, France and Germany, would work out similar agreements with the Israelis.
Although signed by the Bush administration on its last working day, the agreement is binding on the Obama administration.