A "fragile" peace was restored in the Gaza Strip Monday after Israel announced a tentative ceasefire with Hamas and withdrew its troops from Gaza after a 22-day offensive.

The truce, taking effect at 2:00 a.m. local time (0000 GMT) Sunday, was declared late Saturday by Israeli Prime Minister Ehud Olmert, who said the goals of the operation in Gaza had been "met in full."

Right after a ceasefire was declared by both Israel and Gaza militant groups, thousands of Gazans went back to their homes they had fled during the Israeli offensive.

Witnesses in Gaza City said that they saw dozens of Hamas traffic policemen standing at main crossroads in the city to direct traffic.

On Sunday and Monday, the streets in the Gaza Strip, mainly in the densely populated towns and cities, were overcrowded with traffic and pedestrians, just after Israel and Gaza factions had successively declared a ceasefire.

Hundreds of houses were completely or partially destroyed, mainly in Gaza City's neighborhoods of Zeitoon, Tal el-Hawa, Sheja'eya and Tufah, and the houses in the northern Gaza Strip towns of Jabalia and Beit Lahia.

Several local bulldozers are working to clean up the roads to facilitate traffic.

However, fighting did not cease completely, witnesses said. Several missiles were launched by Israeli warships toward the Gaza City, but no casualties were reported.

Israeli radio reported that since the ceasefire began, Israel has allowed 200 trucks loaded with humanitarian aid and industrial fuel to enter Gaza.

Speaking at the inauguration of the first Arab economic summit Monday, UN Secretary-General Ban Ki-moon underscored the importance of an efficient system at Gaza border crossings to allow the inflow of aid, and the need for Palestinians to reconcile and form a united government under President Mahmoud Abbas.

A spokesman for the Israeli military said Israeli troops were expected to pull out of Gaza on Tuesday and Israel would reduce the number of troops stationed in the border.

But Israel will still deploy troops to prevent the offensive of Palestinian militant groups, the spokesman said.

Most Palestinian factions and armed wings, including Hamas, on Sunday accepted a ceasefire and gave Israel a one-week ultimatum to withdraw all its security forces from the whole Gaza Strip and "open the border crossings and lift the Israeli blockade."

The armed wing of the Islamic Hamas movement in Gaza, the al-Qassam Brigades, vowed to continue its armed resistance in the wake of intensified efforts for a ceasefire to end the ongoing Israeli offensive and get more weapons into the Gaza Strip.

The Hamas armed wing's spokesman said: "Since we are legally allowed to bring weapons into Gaza, we know exactly how to bring them." In response, Israel threatened to launch more severe military attacks.

The Palestinian health ministry said 1,300 Palestinians were killed and 5,500 others wounded, most of them civilians, in the offensive. The housing ministry said 4,000 houses had been completely destroyed with 20,000 others damaged.

Countries around the world had called for an immediate end to the military attack and urged all parties concerned to return to the negotiation table to seek a lasting and just settlement to the Palestinian-Israeli conflict.

(Xinhua News Agency January 20, 2009)